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 "extent_io.h"
14 #include "extent_map.h"
17 #include "btrfs_inode.h"
19 static struct kmem_cache *extent_state_cache;
20 static struct kmem_cache *extent_buffer_cache;
22 static LIST_HEAD(buffers);
23 static LIST_HEAD(states);
27 static DEFINE_SPINLOCK(leak_lock);
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;
43 /* tells writepage not to lock the state bits for this range
44 * it still does the unlocking
46 unsigned int extent_locked:1;
48 /* tells the submit_bio code to use a WRITE_SYNC */
49 unsigned int sync_io:1;
52 int __init extent_io_init(void)
54 extent_state_cache = kmem_cache_create("extent_state",
55 sizeof(struct extent_state), 0,
56 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
57 if (!extent_state_cache)
60 extent_buffer_cache = kmem_cache_create("extent_buffers",
61 sizeof(struct extent_buffer), 0,
62 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
63 if (!extent_buffer_cache)
64 goto free_state_cache;
68 kmem_cache_destroy(extent_state_cache);
72 void extent_io_exit(void)
74 struct extent_state *state;
75 struct extent_buffer *eb;
77 while (!list_empty(&states)) {
78 state = list_entry(states.next, struct extent_state, leak_list);
79 printk(KERN_ERR "btrfs state leak: start %llu end %llu "
80 "state %lu in tree %p refs %d\n",
81 (unsigned long long)state->start,
82 (unsigned long long)state->end,
83 state->state, state->tree, atomic_read(&state->refs));
84 list_del(&state->leak_list);
85 kmem_cache_free(extent_state_cache, state);
89 while (!list_empty(&buffers)) {
90 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
91 printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
92 "refs %d\n", (unsigned long long)eb->start,
93 eb->len, atomic_read(&eb->refs));
94 list_del(&eb->leak_list);
95 kmem_cache_free(extent_buffer_cache, eb);
97 if (extent_state_cache)
98 kmem_cache_destroy(extent_state_cache);
99 if (extent_buffer_cache)
100 kmem_cache_destroy(extent_buffer_cache);
103 void extent_io_tree_init(struct extent_io_tree *tree,
104 struct address_space *mapping, gfp_t mask)
106 tree->state = RB_ROOT;
107 INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
109 tree->dirty_bytes = 0;
110 spin_lock_init(&tree->lock);
111 spin_lock_init(&tree->buffer_lock);
112 tree->mapping = mapping;
115 static struct extent_state *alloc_extent_state(gfp_t mask)
117 struct extent_state *state;
122 state = kmem_cache_alloc(extent_state_cache, mask);
129 spin_lock_irqsave(&leak_lock, flags);
130 list_add(&state->leak_list, &states);
131 spin_unlock_irqrestore(&leak_lock, flags);
133 atomic_set(&state->refs, 1);
134 init_waitqueue_head(&state->wq);
138 void free_extent_state(struct extent_state *state)
142 if (atomic_dec_and_test(&state->refs)) {
146 WARN_ON(state->tree);
148 spin_lock_irqsave(&leak_lock, flags);
149 list_del(&state->leak_list);
150 spin_unlock_irqrestore(&leak_lock, flags);
152 kmem_cache_free(extent_state_cache, state);
156 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
157 struct rb_node *node)
159 struct rb_node **p = &root->rb_node;
160 struct rb_node *parent = NULL;
161 struct tree_entry *entry;
165 entry = rb_entry(parent, struct tree_entry, rb_node);
167 if (offset < entry->start)
169 else if (offset > entry->end)
175 entry = rb_entry(node, struct tree_entry, rb_node);
176 rb_link_node(node, parent, p);
177 rb_insert_color(node, root);
181 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
182 struct rb_node **prev_ret,
183 struct rb_node **next_ret)
185 struct rb_root *root = &tree->state;
186 struct rb_node *n = root->rb_node;
187 struct rb_node *prev = NULL;
188 struct rb_node *orig_prev = NULL;
189 struct tree_entry *entry;
190 struct tree_entry *prev_entry = NULL;
193 entry = rb_entry(n, struct tree_entry, rb_node);
197 if (offset < entry->start)
199 else if (offset > entry->end)
207 while (prev && offset > prev_entry->end) {
208 prev = rb_next(prev);
209 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
216 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
217 while (prev && offset < prev_entry->start) {
218 prev = rb_prev(prev);
219 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
226 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
229 struct rb_node *prev = NULL;
232 ret = __etree_search(tree, offset, &prev, NULL);
238 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
239 struct extent_state *other)
241 if (tree->ops && tree->ops->merge_extent_hook)
242 tree->ops->merge_extent_hook(tree->mapping->host, new,
247 * utility function to look for merge candidates inside a given range.
248 * Any extents with matching state are merged together into a single
249 * extent in the tree. Extents with EXTENT_IO in their state field
250 * are not merged because the end_io handlers need to be able to do
251 * operations on them without sleeping (or doing allocations/splits).
253 * This should be called with the tree lock held.
255 static int merge_state(struct extent_io_tree *tree,
256 struct extent_state *state)
258 struct extent_state *other;
259 struct rb_node *other_node;
261 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
264 other_node = rb_prev(&state->rb_node);
266 other = rb_entry(other_node, struct extent_state, rb_node);
267 if (other->end == state->start - 1 &&
268 other->state == state->state) {
269 merge_cb(tree, state, other);
270 state->start = other->start;
272 rb_erase(&other->rb_node, &tree->state);
273 free_extent_state(other);
276 other_node = rb_next(&state->rb_node);
278 other = rb_entry(other_node, struct extent_state, rb_node);
279 if (other->start == state->end + 1 &&
280 other->state == state->state) {
281 merge_cb(tree, state, other);
282 other->start = state->start;
284 rb_erase(&state->rb_node, &tree->state);
285 free_extent_state(state);
293 static int set_state_cb(struct extent_io_tree *tree,
294 struct extent_state *state, int *bits)
296 if (tree->ops && tree->ops->set_bit_hook) {
297 return tree->ops->set_bit_hook(tree->mapping->host,
304 static void clear_state_cb(struct extent_io_tree *tree,
305 struct extent_state *state, int *bits)
307 if (tree->ops && tree->ops->clear_bit_hook)
308 tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
312 * insert an extent_state struct into the tree. 'bits' are set on the
313 * struct before it is inserted.
315 * This may return -EEXIST if the extent is already there, in which case the
316 * state struct is freed.
318 * The tree lock is not taken internally. This is a utility function and
319 * probably isn't what you want to call (see set/clear_extent_bit).
321 static int insert_state(struct extent_io_tree *tree,
322 struct extent_state *state, u64 start, u64 end,
325 struct rb_node *node;
326 int bits_to_set = *bits & ~EXTENT_CTLBITS;
330 printk(KERN_ERR "btrfs end < start %llu %llu\n",
331 (unsigned long long)end,
332 (unsigned long long)start);
335 state->start = start;
337 ret = set_state_cb(tree, state, bits);
341 if (bits_to_set & EXTENT_DIRTY)
342 tree->dirty_bytes += end - start + 1;
343 state->state |= bits_to_set;
344 node = tree_insert(&tree->state, end, &state->rb_node);
346 struct extent_state *found;
347 found = rb_entry(node, struct extent_state, rb_node);
348 printk(KERN_ERR "btrfs found node %llu %llu on insert of "
349 "%llu %llu\n", (unsigned long long)found->start,
350 (unsigned long long)found->end,
351 (unsigned long long)start, (unsigned long long)end);
352 free_extent_state(state);
356 merge_state(tree, state);
360 static int split_cb(struct extent_io_tree *tree, struct extent_state *orig,
363 if (tree->ops && tree->ops->split_extent_hook)
364 return tree->ops->split_extent_hook(tree->mapping->host,
370 * split a given extent state struct in two, inserting the preallocated
371 * struct 'prealloc' as the newly created second half. 'split' indicates an
372 * offset inside 'orig' where it should be split.
375 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
376 * are two extent state structs in the tree:
377 * prealloc: [orig->start, split - 1]
378 * orig: [ split, orig->end ]
380 * The tree locks are not taken by this function. They need to be held
383 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
384 struct extent_state *prealloc, u64 split)
386 struct rb_node *node;
388 split_cb(tree, orig, split);
390 prealloc->start = orig->start;
391 prealloc->end = split - 1;
392 prealloc->state = orig->state;
395 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
397 free_extent_state(prealloc);
400 prealloc->tree = tree;
405 * utility function to clear some bits in an extent state struct.
406 * it will optionally wake up any one waiting on this state (wake == 1), or
407 * forcibly remove the state from the tree (delete == 1).
409 * If no bits are set on the state struct after clearing things, the
410 * struct is freed and removed from the tree
412 static int clear_state_bit(struct extent_io_tree *tree,
413 struct extent_state *state,
416 int bits_to_clear = *bits & ~EXTENT_CTLBITS;
417 int ret = state->state & bits_to_clear;
419 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
420 u64 range = state->end - state->start + 1;
421 WARN_ON(range > tree->dirty_bytes);
422 tree->dirty_bytes -= range;
424 clear_state_cb(tree, state, bits);
425 state->state &= ~bits_to_clear;
428 if (state->state == 0) {
430 rb_erase(&state->rb_node, &tree->state);
432 free_extent_state(state);
437 merge_state(tree, state);
443 * clear some bits on a range in the tree. This may require splitting
444 * or inserting elements in the tree, so the gfp mask is used to
445 * indicate which allocations or sleeping are allowed.
447 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
448 * the given range from the tree regardless of state (ie for truncate).
450 * the range [start, end] is inclusive.
452 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
453 * bits were already set, or zero if none of the bits were already set.
455 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
456 int bits, int wake, int delete,
457 struct extent_state **cached_state,
460 struct extent_state *state;
461 struct extent_state *cached;
462 struct extent_state *prealloc = NULL;
463 struct rb_node *next_node;
464 struct rb_node *node;
471 bits |= ~EXTENT_CTLBITS;
472 bits |= EXTENT_FIRST_DELALLOC;
474 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
477 if (!prealloc && (mask & __GFP_WAIT)) {
478 prealloc = alloc_extent_state(mask);
483 spin_lock(&tree->lock);
485 cached = *cached_state;
488 *cached_state = NULL;
492 if (cached && cached->tree && cached->start == start) {
494 atomic_dec(&cached->refs);
499 free_extent_state(cached);
502 * this search will find the extents that end after
505 node = tree_search(tree, start);
508 state = rb_entry(node, struct extent_state, rb_node);
510 if (state->start > end)
512 WARN_ON(state->end < start);
513 last_end = state->end;
516 * | ---- desired range ---- |
518 * | ------------- state -------------- |
520 * We need to split the extent we found, and may flip
521 * bits on second half.
523 * If the extent we found extends past our range, we
524 * just split and search again. It'll get split again
525 * the next time though.
527 * If the extent we found is inside our range, we clear
528 * the desired bit on it.
531 if (state->start < start) {
533 prealloc = alloc_extent_state(GFP_ATOMIC);
534 err = split_state(tree, state, prealloc, start);
535 BUG_ON(err == -EEXIST);
539 if (state->end <= end) {
540 set |= clear_state_bit(tree, state, &bits, wake);
541 if (last_end == (u64)-1)
543 start = last_end + 1;
548 * | ---- desired range ---- |
550 * We need to split the extent, and clear the bit
553 if (state->start <= end && state->end > end) {
555 prealloc = alloc_extent_state(GFP_ATOMIC);
556 err = split_state(tree, state, prealloc, end + 1);
557 BUG_ON(err == -EEXIST);
561 set |= clear_state_bit(tree, prealloc, &bits, wake);
567 if (state->end < end && prealloc && !need_resched())
568 next_node = rb_next(&state->rb_node);
572 set |= clear_state_bit(tree, state, &bits, wake);
573 if (last_end == (u64)-1)
575 start = last_end + 1;
576 if (start <= end && next_node) {
577 state = rb_entry(next_node, struct extent_state,
579 if (state->start == start)
585 spin_unlock(&tree->lock);
587 free_extent_state(prealloc);
594 spin_unlock(&tree->lock);
595 if (mask & __GFP_WAIT)
600 static int wait_on_state(struct extent_io_tree *tree,
601 struct extent_state *state)
602 __releases(tree->lock)
603 __acquires(tree->lock)
606 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
607 spin_unlock(&tree->lock);
609 spin_lock(&tree->lock);
610 finish_wait(&state->wq, &wait);
615 * waits for one or more bits to clear on a range in the state tree.
616 * The range [start, end] is inclusive.
617 * The tree lock is taken by this function
619 int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
621 struct extent_state *state;
622 struct rb_node *node;
624 spin_lock(&tree->lock);
628 * this search will find all the extents that end after
631 node = tree_search(tree, start);
635 state = rb_entry(node, struct extent_state, rb_node);
637 if (state->start > end)
640 if (state->state & bits) {
641 start = state->start;
642 atomic_inc(&state->refs);
643 wait_on_state(tree, state);
644 free_extent_state(state);
647 start = state->end + 1;
652 if (need_resched()) {
653 spin_unlock(&tree->lock);
655 spin_lock(&tree->lock);
659 spin_unlock(&tree->lock);
663 static int set_state_bits(struct extent_io_tree *tree,
664 struct extent_state *state,
668 int bits_to_set = *bits & ~EXTENT_CTLBITS;
670 ret = set_state_cb(tree, state, bits);
673 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
674 u64 range = state->end - state->start + 1;
675 tree->dirty_bytes += range;
677 state->state |= bits_to_set;
682 static void cache_state(struct extent_state *state,
683 struct extent_state **cached_ptr)
685 if (cached_ptr && !(*cached_ptr)) {
686 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
688 atomic_inc(&state->refs);
694 * set some bits on a range in the tree. This may require allocations or
695 * sleeping, so the gfp mask is used to indicate what is allowed.
697 * If any of the exclusive bits are set, this will fail with -EEXIST if some
698 * part of the range already has the desired bits set. The start of the
699 * existing range is returned in failed_start in this case.
701 * [start, end] is inclusive This takes the tree lock.
704 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
705 int bits, int exclusive_bits, u64 *failed_start,
706 struct extent_state **cached_state, gfp_t mask)
708 struct extent_state *state;
709 struct extent_state *prealloc = NULL;
710 struct rb_node *node;
715 bits |= EXTENT_FIRST_DELALLOC;
717 if (!prealloc && (mask & __GFP_WAIT)) {
718 prealloc = alloc_extent_state(mask);
723 spin_lock(&tree->lock);
724 if (cached_state && *cached_state) {
725 state = *cached_state;
726 if (state->start == start && state->tree) {
727 node = &state->rb_node;
732 * this search will find all the extents that end after
735 node = tree_search(tree, start);
737 err = insert_state(tree, prealloc, start, end, &bits);
739 BUG_ON(err == -EEXIST);
742 state = rb_entry(node, struct extent_state, rb_node);
744 last_start = state->start;
745 last_end = state->end;
748 * | ---- desired range ---- |
751 * Just lock what we found and keep going
753 if (state->start == start && state->end <= end) {
754 struct rb_node *next_node;
755 if (state->state & exclusive_bits) {
756 *failed_start = state->start;
761 err = set_state_bits(tree, state, &bits);
765 cache_state(state, cached_state);
766 merge_state(tree, state);
767 if (last_end == (u64)-1)
770 start = last_end + 1;
771 if (start < end && prealloc && !need_resched()) {
772 next_node = rb_next(node);
774 state = rb_entry(next_node, struct extent_state,
776 if (state->start == start)
784 * | ---- desired range ---- |
787 * | ------------- state -------------- |
789 * We need to split the extent we found, and may flip bits on
792 * If the extent we found extends past our
793 * range, we just split and search again. It'll get split
794 * again the next time though.
796 * If the extent we found is inside our range, we set the
799 if (state->start < start) {
800 if (state->state & exclusive_bits) {
801 *failed_start = start;
805 err = split_state(tree, state, prealloc, start);
806 BUG_ON(err == -EEXIST);
810 if (state->end <= end) {
811 err = set_state_bits(tree, state, &bits);
814 cache_state(state, cached_state);
815 merge_state(tree, state);
816 if (last_end == (u64)-1)
818 start = last_end + 1;
823 * | ---- desired range ---- |
824 * | state | or | state |
826 * There's a hole, we need to insert something in it and
827 * ignore the extent we found.
829 if (state->start > start) {
831 if (end < last_start)
834 this_end = last_start - 1;
835 err = insert_state(tree, prealloc, start, this_end,
837 BUG_ON(err == -EEXIST);
842 cache_state(prealloc, cached_state);
844 start = this_end + 1;
848 * | ---- desired range ---- |
850 * We need to split the extent, and set the bit
853 if (state->start <= end && state->end > end) {
854 if (state->state & exclusive_bits) {
855 *failed_start = start;
859 err = split_state(tree, state, prealloc, end + 1);
860 BUG_ON(err == -EEXIST);
862 err = set_state_bits(tree, prealloc, &bits);
867 cache_state(prealloc, cached_state);
868 merge_state(tree, prealloc);
876 spin_unlock(&tree->lock);
878 free_extent_state(prealloc);
885 spin_unlock(&tree->lock);
886 if (mask & __GFP_WAIT)
891 /* wrappers around set/clear extent bit */
892 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
895 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
899 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
900 int bits, gfp_t mask)
902 return set_extent_bit(tree, start, end, bits, 0, NULL,
906 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
907 int bits, gfp_t mask)
909 return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
912 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
913 struct extent_state **cached_state, gfp_t mask)
915 return set_extent_bit(tree, start, end,
916 EXTENT_DELALLOC | EXTENT_DIRTY | EXTENT_UPTODATE,
917 0, NULL, cached_state, mask);
920 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
923 return clear_extent_bit(tree, start, end,
924 EXTENT_DIRTY | EXTENT_DELALLOC |
925 EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
928 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
931 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
935 static int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
938 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0,
942 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
945 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
949 static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
950 u64 end, struct extent_state **cached_state,
953 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
957 int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end)
959 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
963 * either insert or lock state struct between start and end use mask to tell
964 * us if waiting is desired.
966 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
967 int bits, struct extent_state **cached_state, gfp_t mask)
972 err = set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
973 EXTENT_LOCKED, &failed_start,
975 if (err == -EEXIST && (mask & __GFP_WAIT)) {
976 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
977 start = failed_start;
981 WARN_ON(start > end);
986 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
988 return lock_extent_bits(tree, start, end, 0, NULL, mask);
991 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
997 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
998 &failed_start, NULL, mask);
999 if (err == -EEXIST) {
1000 if (failed_start > start)
1001 clear_extent_bit(tree, start, failed_start - 1,
1002 EXTENT_LOCKED, 1, 0, NULL, mask);
1008 int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
1009 struct extent_state **cached, gfp_t mask)
1011 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
1015 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
1018 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
1023 * helper function to set pages and extents in the tree dirty
1025 int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end)
1027 unsigned long index = start >> PAGE_CACHE_SHIFT;
1028 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1031 while (index <= end_index) {
1032 page = find_get_page(tree->mapping, index);
1034 __set_page_dirty_nobuffers(page);
1035 page_cache_release(page);
1042 * helper function to set both pages and extents in the tree writeback
1044 static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1046 unsigned long index = start >> PAGE_CACHE_SHIFT;
1047 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1050 while (index <= end_index) {
1051 page = find_get_page(tree->mapping, index);
1053 set_page_writeback(page);
1054 page_cache_release(page);
1061 * find the first offset in the io tree with 'bits' set. zero is
1062 * returned if we find something, and *start_ret and *end_ret are
1063 * set to reflect the state struct that was found.
1065 * If nothing was found, 1 is returned, < 0 on error
1067 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1068 u64 *start_ret, u64 *end_ret, int bits)
1070 struct rb_node *node;
1071 struct extent_state *state;
1074 spin_lock(&tree->lock);
1076 * this search will find all the extents that end after
1079 node = tree_search(tree, start);
1084 state = rb_entry(node, struct extent_state, rb_node);
1085 if (state->end >= start && (state->state & bits)) {
1086 *start_ret = state->start;
1087 *end_ret = state->end;
1091 node = rb_next(node);
1096 spin_unlock(&tree->lock);
1100 /* find the first state struct with 'bits' set after 'start', and
1101 * return it. tree->lock must be held. NULL will returned if
1102 * nothing was found after 'start'
1104 struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
1105 u64 start, int bits)
1107 struct rb_node *node;
1108 struct extent_state *state;
1111 * this search will find all the extents that end after
1114 node = tree_search(tree, start);
1119 state = rb_entry(node, struct extent_state, rb_node);
1120 if (state->end >= start && (state->state & bits))
1123 node = rb_next(node);
1132 * find a contiguous range of bytes in the file marked as delalloc, not
1133 * more than 'max_bytes'. start and end are used to return the range,
1135 * 1 is returned if we find something, 0 if nothing was in the tree
1137 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1138 u64 *start, u64 *end, u64 max_bytes,
1139 struct extent_state **cached_state)
1141 struct rb_node *node;
1142 struct extent_state *state;
1143 u64 cur_start = *start;
1145 u64 total_bytes = 0;
1147 spin_lock(&tree->lock);
1150 * this search will find all the extents that end after
1153 node = tree_search(tree, cur_start);
1161 state = rb_entry(node, struct extent_state, rb_node);
1162 if (found && (state->start != cur_start ||
1163 (state->state & EXTENT_BOUNDARY))) {
1166 if (!(state->state & EXTENT_DELALLOC)) {
1172 *start = state->start;
1173 *cached_state = state;
1174 atomic_inc(&state->refs);
1178 cur_start = state->end + 1;
1179 node = rb_next(node);
1182 total_bytes += state->end - state->start + 1;
1183 if (total_bytes >= max_bytes)
1187 spin_unlock(&tree->lock);
1191 static noinline int __unlock_for_delalloc(struct inode *inode,
1192 struct page *locked_page,
1196 struct page *pages[16];
1197 unsigned long index = start >> PAGE_CACHE_SHIFT;
1198 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1199 unsigned long nr_pages = end_index - index + 1;
1202 if (index == locked_page->index && end_index == index)
1205 while (nr_pages > 0) {
1206 ret = find_get_pages_contig(inode->i_mapping, index,
1207 min_t(unsigned long, nr_pages,
1208 ARRAY_SIZE(pages)), pages);
1209 for (i = 0; i < ret; i++) {
1210 if (pages[i] != locked_page)
1211 unlock_page(pages[i]);
1212 page_cache_release(pages[i]);
1221 static noinline int lock_delalloc_pages(struct inode *inode,
1222 struct page *locked_page,
1226 unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
1227 unsigned long start_index = index;
1228 unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
1229 unsigned long pages_locked = 0;
1230 struct page *pages[16];
1231 unsigned long nrpages;
1235 /* the caller is responsible for locking the start index */
1236 if (index == locked_page->index && index == end_index)
1239 /* skip the page at the start index */
1240 nrpages = end_index - index + 1;
1241 while (nrpages > 0) {
1242 ret = find_get_pages_contig(inode->i_mapping, index,
1243 min_t(unsigned long,
1244 nrpages, ARRAY_SIZE(pages)), pages);
1249 /* now we have an array of pages, lock them all */
1250 for (i = 0; i < ret; i++) {
1252 * the caller is taking responsibility for
1255 if (pages[i] != locked_page) {
1256 lock_page(pages[i]);
1257 if (!PageDirty(pages[i]) ||
1258 pages[i]->mapping != inode->i_mapping) {
1260 unlock_page(pages[i]);
1261 page_cache_release(pages[i]);
1265 page_cache_release(pages[i]);
1274 if (ret && pages_locked) {
1275 __unlock_for_delalloc(inode, locked_page,
1277 ((u64)(start_index + pages_locked - 1)) <<
1284 * find a contiguous range of bytes in the file marked as delalloc, not
1285 * more than 'max_bytes'. start and end are used to return the range,
1287 * 1 is returned if we find something, 0 if nothing was in the tree
1289 static noinline u64 find_lock_delalloc_range(struct inode *inode,
1290 struct extent_io_tree *tree,
1291 struct page *locked_page,
1292 u64 *start, u64 *end,
1298 struct extent_state *cached_state = NULL;
1303 /* step one, find a bunch of delalloc bytes starting at start */
1304 delalloc_start = *start;
1306 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1307 max_bytes, &cached_state);
1308 if (!found || delalloc_end <= *start) {
1309 *start = delalloc_start;
1310 *end = delalloc_end;
1311 free_extent_state(cached_state);
1316 * start comes from the offset of locked_page. We have to lock
1317 * pages in order, so we can't process delalloc bytes before
1320 if (delalloc_start < *start)
1321 delalloc_start = *start;
1324 * make sure to limit the number of pages we try to lock down
1327 if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1328 delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
1330 /* step two, lock all the pages after the page that has start */
1331 ret = lock_delalloc_pages(inode, locked_page,
1332 delalloc_start, delalloc_end);
1333 if (ret == -EAGAIN) {
1334 /* some of the pages are gone, lets avoid looping by
1335 * shortening the size of the delalloc range we're searching
1337 free_extent_state(cached_state);
1339 unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
1340 max_bytes = PAGE_CACHE_SIZE - offset;
1350 /* step three, lock the state bits for the whole range */
1351 lock_extent_bits(tree, delalloc_start, delalloc_end,
1352 0, &cached_state, GFP_NOFS);
1354 /* then test to make sure it is all still delalloc */
1355 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1356 EXTENT_DELALLOC, 1, cached_state);
1358 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1359 &cached_state, GFP_NOFS);
1360 __unlock_for_delalloc(inode, locked_page,
1361 delalloc_start, delalloc_end);
1365 free_extent_state(cached_state);
1366 *start = delalloc_start;
1367 *end = delalloc_end;
1372 int extent_clear_unlock_delalloc(struct inode *inode,
1373 struct extent_io_tree *tree,
1374 u64 start, u64 end, struct page *locked_page,
1378 struct page *pages[16];
1379 unsigned long index = start >> PAGE_CACHE_SHIFT;
1380 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1381 unsigned long nr_pages = end_index - index + 1;
1385 if (op & EXTENT_CLEAR_UNLOCK)
1386 clear_bits |= EXTENT_LOCKED;
1387 if (op & EXTENT_CLEAR_DIRTY)
1388 clear_bits |= EXTENT_DIRTY;
1390 if (op & EXTENT_CLEAR_DELALLOC)
1391 clear_bits |= EXTENT_DELALLOC;
1393 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1394 if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
1395 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
1396 EXTENT_SET_PRIVATE2)))
1399 while (nr_pages > 0) {
1400 ret = find_get_pages_contig(inode->i_mapping, index,
1401 min_t(unsigned long,
1402 nr_pages, ARRAY_SIZE(pages)), pages);
1403 for (i = 0; i < ret; i++) {
1405 if (op & EXTENT_SET_PRIVATE2)
1406 SetPagePrivate2(pages[i]);
1408 if (pages[i] == locked_page) {
1409 page_cache_release(pages[i]);
1412 if (op & EXTENT_CLEAR_DIRTY)
1413 clear_page_dirty_for_io(pages[i]);
1414 if (op & EXTENT_SET_WRITEBACK)
1415 set_page_writeback(pages[i]);
1416 if (op & EXTENT_END_WRITEBACK)
1417 end_page_writeback(pages[i]);
1418 if (op & EXTENT_CLEAR_UNLOCK_PAGE)
1419 unlock_page(pages[i]);
1420 page_cache_release(pages[i]);
1430 * count the number of bytes in the tree that have a given bit(s)
1431 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1432 * cached. The total number found is returned.
1434 u64 count_range_bits(struct extent_io_tree *tree,
1435 u64 *start, u64 search_end, u64 max_bytes,
1436 unsigned long bits, int contig)
1438 struct rb_node *node;
1439 struct extent_state *state;
1440 u64 cur_start = *start;
1441 u64 total_bytes = 0;
1445 if (search_end <= cur_start) {
1450 spin_lock(&tree->lock);
1451 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1452 total_bytes = tree->dirty_bytes;
1456 * this search will find all the extents that end after
1459 node = tree_search(tree, cur_start);
1464 state = rb_entry(node, struct extent_state, rb_node);
1465 if (state->start > search_end)
1467 if (contig && found && state->start > last + 1)
1469 if (state->end >= cur_start && (state->state & bits) == bits) {
1470 total_bytes += min(search_end, state->end) + 1 -
1471 max(cur_start, state->start);
1472 if (total_bytes >= max_bytes)
1475 *start = state->start;
1479 } else if (contig && found) {
1482 node = rb_next(node);
1487 spin_unlock(&tree->lock);
1492 * set the private field for a given byte offset in the tree. If there isn't
1493 * an extent_state there already, this does nothing.
1495 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1497 struct rb_node *node;
1498 struct extent_state *state;
1501 spin_lock(&tree->lock);
1503 * this search will find all the extents that end after
1506 node = tree_search(tree, start);
1511 state = rb_entry(node, struct extent_state, rb_node);
1512 if (state->start != start) {
1516 state->private = private;
1518 spin_unlock(&tree->lock);
1522 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1524 struct rb_node *node;
1525 struct extent_state *state;
1528 spin_lock(&tree->lock);
1530 * this search will find all the extents that end after
1533 node = tree_search(tree, start);
1538 state = rb_entry(node, struct extent_state, rb_node);
1539 if (state->start != start) {
1543 *private = state->private;
1545 spin_unlock(&tree->lock);
1550 * searches a range in the state tree for a given mask.
1551 * If 'filled' == 1, this returns 1 only if every extent in the tree
1552 * has the bits set. Otherwise, 1 is returned if any bit in the
1553 * range is found set.
1555 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1556 int bits, int filled, struct extent_state *cached)
1558 struct extent_state *state = NULL;
1559 struct rb_node *node;
1562 spin_lock(&tree->lock);
1563 if (cached && cached->tree && cached->start == start)
1564 node = &cached->rb_node;
1566 node = tree_search(tree, start);
1567 while (node && start <= end) {
1568 state = rb_entry(node, struct extent_state, rb_node);
1570 if (filled && state->start > start) {
1575 if (state->start > end)
1578 if (state->state & bits) {
1582 } else if (filled) {
1587 if (state->end == (u64)-1)
1590 start = state->end + 1;
1593 node = rb_next(node);
1600 spin_unlock(&tree->lock);
1605 * helper function to set a given page up to date if all the
1606 * extents in the tree for that page are up to date
1608 static int check_page_uptodate(struct extent_io_tree *tree,
1611 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1612 u64 end = start + PAGE_CACHE_SIZE - 1;
1613 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1614 SetPageUptodate(page);
1619 * helper function to unlock a page if all the extents in the tree
1620 * for that page are unlocked
1622 static int check_page_locked(struct extent_io_tree *tree,
1625 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1626 u64 end = start + PAGE_CACHE_SIZE - 1;
1627 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
1633 * helper function to end page writeback if all the extents
1634 * in the tree for that page are done with writeback
1636 static int check_page_writeback(struct extent_io_tree *tree,
1639 end_page_writeback(page);
1643 /* lots and lots of room for performance fixes in the end_bio funcs */
1646 * after a writepage IO is done, we need to:
1647 * clear the uptodate bits on error
1648 * clear the writeback bits in the extent tree for this IO
1649 * end_page_writeback if the page has no more pending IO
1651 * Scheduling is not allowed, so the extent state tree is expected
1652 * to have one and only one object corresponding to this IO.
1654 static void end_bio_extent_writepage(struct bio *bio, int err)
1656 int uptodate = err == 0;
1657 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1658 struct extent_io_tree *tree;
1665 struct page *page = bvec->bv_page;
1666 tree = &BTRFS_I(page->mapping->host)->io_tree;
1668 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1670 end = start + bvec->bv_len - 1;
1672 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1677 if (--bvec >= bio->bi_io_vec)
1678 prefetchw(&bvec->bv_page->flags);
1679 if (tree->ops && tree->ops->writepage_end_io_hook) {
1680 ret = tree->ops->writepage_end_io_hook(page, start,
1681 end, NULL, uptodate);
1686 if (!uptodate && tree->ops &&
1687 tree->ops->writepage_io_failed_hook) {
1688 ret = tree->ops->writepage_io_failed_hook(bio, page,
1691 uptodate = (err == 0);
1697 clear_extent_uptodate(tree, start, end, NULL, GFP_NOFS);
1698 ClearPageUptodate(page);
1703 end_page_writeback(page);
1705 check_page_writeback(tree, page);
1706 } while (bvec >= bio->bi_io_vec);
1712 * after a readpage IO is done, we need to:
1713 * clear the uptodate bits on error
1714 * set the uptodate bits if things worked
1715 * set the page up to date if all extents in the tree are uptodate
1716 * clear the lock bit in the extent tree
1717 * unlock the page if there are no other extents locked for it
1719 * Scheduling is not allowed, so the extent state tree is expected
1720 * to have one and only one object corresponding to this IO.
1722 static void end_bio_extent_readpage(struct bio *bio, int err)
1724 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1725 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
1726 struct bio_vec *bvec = bio->bi_io_vec;
1727 struct extent_io_tree *tree;
1737 struct page *page = bvec->bv_page;
1738 tree = &BTRFS_I(page->mapping->host)->io_tree;
1740 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1742 end = start + bvec->bv_len - 1;
1744 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1749 if (++bvec <= bvec_end)
1750 prefetchw(&bvec->bv_page->flags);
1752 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
1753 ret = tree->ops->readpage_end_io_hook(page, start, end,
1758 if (!uptodate && tree->ops &&
1759 tree->ops->readpage_io_failed_hook) {
1760 ret = tree->ops->readpage_io_failed_hook(bio, page,
1764 test_bit(BIO_UPTODATE, &bio->bi_flags);
1772 set_extent_uptodate(tree, start, end,
1775 unlock_extent(tree, start, end, GFP_ATOMIC);
1779 SetPageUptodate(page);
1781 ClearPageUptodate(page);
1787 check_page_uptodate(tree, page);
1789 ClearPageUptodate(page);
1792 check_page_locked(tree, page);
1794 } while (bvec <= bvec_end);
1800 * IO done from prepare_write is pretty simple, we just unlock
1801 * the structs in the extent tree when done, and set the uptodate bits
1804 static void end_bio_extent_preparewrite(struct bio *bio, int err)
1806 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1807 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1808 struct extent_io_tree *tree;
1813 struct page *page = bvec->bv_page;
1814 tree = &BTRFS_I(page->mapping->host)->io_tree;
1816 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1818 end = start + bvec->bv_len - 1;
1820 if (--bvec >= bio->bi_io_vec)
1821 prefetchw(&bvec->bv_page->flags);
1824 set_extent_uptodate(tree, start, end, GFP_ATOMIC);
1826 ClearPageUptodate(page);
1830 unlock_extent(tree, start, end, GFP_ATOMIC);
1832 } while (bvec >= bio->bi_io_vec);
1838 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
1843 bio = bio_alloc(gfp_flags, nr_vecs);
1845 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
1846 while (!bio && (nr_vecs /= 2))
1847 bio = bio_alloc(gfp_flags, nr_vecs);
1852 bio->bi_bdev = bdev;
1853 bio->bi_sector = first_sector;
1858 static int submit_one_bio(int rw, struct bio *bio, int mirror_num,
1859 unsigned long bio_flags)
1862 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1863 struct page *page = bvec->bv_page;
1864 struct extent_io_tree *tree = bio->bi_private;
1867 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1869 bio->bi_private = NULL;
1873 if (tree->ops && tree->ops->submit_bio_hook)
1874 ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
1875 mirror_num, bio_flags, start);
1877 submit_bio(rw, bio);
1878 if (bio_flagged(bio, BIO_EOPNOTSUPP))
1884 static int submit_extent_page(int rw, struct extent_io_tree *tree,
1885 struct page *page, sector_t sector,
1886 size_t size, unsigned long offset,
1887 struct block_device *bdev,
1888 struct bio **bio_ret,
1889 unsigned long max_pages,
1890 bio_end_io_t end_io_func,
1892 unsigned long prev_bio_flags,
1893 unsigned long bio_flags)
1899 int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
1900 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
1901 size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
1903 if (bio_ret && *bio_ret) {
1906 contig = bio->bi_sector == sector;
1908 contig = bio->bi_sector + (bio->bi_size >> 9) ==
1911 if (prev_bio_flags != bio_flags || !contig ||
1912 (tree->ops && tree->ops->merge_bio_hook &&
1913 tree->ops->merge_bio_hook(page, offset, page_size, bio,
1915 bio_add_page(bio, page, page_size, offset) < page_size) {
1916 ret = submit_one_bio(rw, bio, mirror_num,
1923 if (this_compressed)
1926 nr = bio_get_nr_vecs(bdev);
1928 bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
1932 bio_add_page(bio, page, page_size, offset);
1933 bio->bi_end_io = end_io_func;
1934 bio->bi_private = tree;
1939 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
1944 void set_page_extent_mapped(struct page *page)
1946 if (!PagePrivate(page)) {
1947 SetPagePrivate(page);
1948 page_cache_get(page);
1949 set_page_private(page, EXTENT_PAGE_PRIVATE);
1953 static void set_page_extent_head(struct page *page, unsigned long len)
1955 WARN_ON(!PagePrivate(page));
1956 set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
1960 * basic readpage implementation. Locked extent state structs are inserted
1961 * into the tree that are removed when the IO is done (by the end_io
1964 static int __extent_read_full_page(struct extent_io_tree *tree,
1966 get_extent_t *get_extent,
1967 struct bio **bio, int mirror_num,
1968 unsigned long *bio_flags)
1970 struct inode *inode = page->mapping->host;
1971 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1972 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1976 u64 last_byte = i_size_read(inode);
1980 struct extent_map *em;
1981 struct block_device *bdev;
1982 struct btrfs_ordered_extent *ordered;
1985 size_t page_offset = 0;
1987 size_t disk_io_size;
1988 size_t blocksize = inode->i_sb->s_blocksize;
1989 unsigned long this_bio_flag = 0;
1991 set_page_extent_mapped(page);
1995 lock_extent(tree, start, end, GFP_NOFS);
1996 ordered = btrfs_lookup_ordered_extent(inode, start);
1999 unlock_extent(tree, start, end, GFP_NOFS);
2000 btrfs_start_ordered_extent(inode, ordered, 1);
2001 btrfs_put_ordered_extent(ordered);
2004 if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
2006 size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
2009 iosize = PAGE_CACHE_SIZE - zero_offset;
2010 userpage = kmap_atomic(page, KM_USER0);
2011 memset(userpage + zero_offset, 0, iosize);
2012 flush_dcache_page(page);
2013 kunmap_atomic(userpage, KM_USER0);
2016 while (cur <= end) {
2017 if (cur >= last_byte) {
2019 iosize = PAGE_CACHE_SIZE - page_offset;
2020 userpage = kmap_atomic(page, KM_USER0);
2021 memset(userpage + page_offset, 0, iosize);
2022 flush_dcache_page(page);
2023 kunmap_atomic(userpage, KM_USER0);
2024 set_extent_uptodate(tree, cur, cur + iosize - 1,
2026 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2029 em = get_extent(inode, page, page_offset, cur,
2031 if (IS_ERR(em) || !em) {
2033 unlock_extent(tree, cur, end, GFP_NOFS);
2036 extent_offset = cur - em->start;
2037 BUG_ON(extent_map_end(em) <= cur);
2040 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2041 this_bio_flag = EXTENT_BIO_COMPRESSED;
2042 extent_set_compress_type(&this_bio_flag,
2046 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2047 cur_end = min(extent_map_end(em) - 1, end);
2048 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2049 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2050 disk_io_size = em->block_len;
2051 sector = em->block_start >> 9;
2053 sector = (em->block_start + extent_offset) >> 9;
2054 disk_io_size = iosize;
2057 block_start = em->block_start;
2058 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2059 block_start = EXTENT_MAP_HOLE;
2060 free_extent_map(em);
2063 /* we've found a hole, just zero and go on */
2064 if (block_start == EXTENT_MAP_HOLE) {
2066 userpage = kmap_atomic(page, KM_USER0);
2067 memset(userpage + page_offset, 0, iosize);
2068 flush_dcache_page(page);
2069 kunmap_atomic(userpage, KM_USER0);
2071 set_extent_uptodate(tree, cur, cur + iosize - 1,
2073 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2075 page_offset += iosize;
2078 /* the get_extent function already copied into the page */
2079 if (test_range_bit(tree, cur, cur_end,
2080 EXTENT_UPTODATE, 1, NULL)) {
2081 check_page_uptodate(tree, page);
2082 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2084 page_offset += iosize;
2087 /* we have an inline extent but it didn't get marked up
2088 * to date. Error out
2090 if (block_start == EXTENT_MAP_INLINE) {
2092 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2094 page_offset += iosize;
2099 if (tree->ops && tree->ops->readpage_io_hook) {
2100 ret = tree->ops->readpage_io_hook(page, cur,
2104 unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
2106 ret = submit_extent_page(READ, tree, page,
2107 sector, disk_io_size, page_offset,
2109 end_bio_extent_readpage, mirror_num,
2113 *bio_flags = this_bio_flag;
2118 page_offset += iosize;
2121 if (!PageError(page))
2122 SetPageUptodate(page);
2128 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
2129 get_extent_t *get_extent)
2131 struct bio *bio = NULL;
2132 unsigned long bio_flags = 0;
2135 ret = __extent_read_full_page(tree, page, get_extent, &bio, 0,
2138 ret = submit_one_bio(READ, bio, 0, bio_flags);
2142 static noinline void update_nr_written(struct page *page,
2143 struct writeback_control *wbc,
2144 unsigned long nr_written)
2146 wbc->nr_to_write -= nr_written;
2147 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
2148 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
2149 page->mapping->writeback_index = page->index + nr_written;
2153 * the writepage semantics are similar to regular writepage. extent
2154 * records are inserted to lock ranges in the tree, and as dirty areas
2155 * are found, they are marked writeback. Then the lock bits are removed
2156 * and the end_io handler clears the writeback ranges
2158 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
2161 struct inode *inode = page->mapping->host;
2162 struct extent_page_data *epd = data;
2163 struct extent_io_tree *tree = epd->tree;
2164 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2166 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2170 u64 last_byte = i_size_read(inode);
2174 struct extent_state *cached_state = NULL;
2175 struct extent_map *em;
2176 struct block_device *bdev;
2179 size_t pg_offset = 0;
2181 loff_t i_size = i_size_read(inode);
2182 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
2188 unsigned long nr_written = 0;
2190 if (wbc->sync_mode == WB_SYNC_ALL)
2191 write_flags = WRITE_SYNC;
2193 write_flags = WRITE;
2195 trace___extent_writepage(page, inode, wbc);
2197 WARN_ON(!PageLocked(page));
2198 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2199 if (page->index > end_index ||
2200 (page->index == end_index && !pg_offset)) {
2201 page->mapping->a_ops->invalidatepage(page, 0);
2206 if (page->index == end_index) {
2209 userpage = kmap_atomic(page, KM_USER0);
2210 memset(userpage + pg_offset, 0,
2211 PAGE_CACHE_SIZE - pg_offset);
2212 kunmap_atomic(userpage, KM_USER0);
2213 flush_dcache_page(page);
2217 set_page_extent_mapped(page);
2219 delalloc_start = start;
2222 if (!epd->extent_locked) {
2223 u64 delalloc_to_write = 0;
2225 * make sure the wbc mapping index is at least updated
2228 update_nr_written(page, wbc, 0);
2230 while (delalloc_end < page_end) {
2231 nr_delalloc = find_lock_delalloc_range(inode, tree,
2236 if (nr_delalloc == 0) {
2237 delalloc_start = delalloc_end + 1;
2240 tree->ops->fill_delalloc(inode, page, delalloc_start,
2241 delalloc_end, &page_started,
2244 * delalloc_end is already one less than the total
2245 * length, so we don't subtract one from
2248 delalloc_to_write += (delalloc_end - delalloc_start +
2251 delalloc_start = delalloc_end + 1;
2253 if (wbc->nr_to_write < delalloc_to_write) {
2256 if (delalloc_to_write < thresh * 2)
2257 thresh = delalloc_to_write;
2258 wbc->nr_to_write = min_t(u64, delalloc_to_write,
2262 /* did the fill delalloc function already unlock and start
2268 * we've unlocked the page, so we can't update
2269 * the mapping's writeback index, just update
2272 wbc->nr_to_write -= nr_written;
2276 if (tree->ops && tree->ops->writepage_start_hook) {
2277 ret = tree->ops->writepage_start_hook(page, start,
2279 if (ret == -EAGAIN) {
2280 redirty_page_for_writepage(wbc, page);
2281 update_nr_written(page, wbc, nr_written);
2289 * we don't want to touch the inode after unlocking the page,
2290 * so we update the mapping writeback index now
2292 update_nr_written(page, wbc, nr_written + 1);
2295 if (last_byte <= start) {
2296 if (tree->ops && tree->ops->writepage_end_io_hook)
2297 tree->ops->writepage_end_io_hook(page, start,
2302 blocksize = inode->i_sb->s_blocksize;
2304 while (cur <= end) {
2305 if (cur >= last_byte) {
2306 if (tree->ops && tree->ops->writepage_end_io_hook)
2307 tree->ops->writepage_end_io_hook(page, cur,
2311 em = epd->get_extent(inode, page, pg_offset, cur,
2313 if (IS_ERR(em) || !em) {
2318 extent_offset = cur - em->start;
2319 BUG_ON(extent_map_end(em) <= cur);
2321 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2322 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2323 sector = (em->block_start + extent_offset) >> 9;
2325 block_start = em->block_start;
2326 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
2327 free_extent_map(em);
2331 * compressed and inline extents are written through other
2334 if (compressed || block_start == EXTENT_MAP_HOLE ||
2335 block_start == EXTENT_MAP_INLINE) {
2337 * end_io notification does not happen here for
2338 * compressed extents
2340 if (!compressed && tree->ops &&
2341 tree->ops->writepage_end_io_hook)
2342 tree->ops->writepage_end_io_hook(page, cur,
2345 else if (compressed) {
2346 /* we don't want to end_page_writeback on
2347 * a compressed extent. this happens
2354 pg_offset += iosize;
2357 /* leave this out until we have a page_mkwrite call */
2358 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
2359 EXTENT_DIRTY, 0, NULL)) {
2361 pg_offset += iosize;
2365 if (tree->ops && tree->ops->writepage_io_hook) {
2366 ret = tree->ops->writepage_io_hook(page, cur,
2374 unsigned long max_nr = end_index + 1;
2376 set_range_writeback(tree, cur, cur + iosize - 1);
2377 if (!PageWriteback(page)) {
2378 printk(KERN_ERR "btrfs warning page %lu not "
2379 "writeback, cur %llu end %llu\n",
2380 page->index, (unsigned long long)cur,
2381 (unsigned long long)end);
2384 ret = submit_extent_page(write_flags, tree, page,
2385 sector, iosize, pg_offset,
2386 bdev, &epd->bio, max_nr,
2387 end_bio_extent_writepage,
2393 pg_offset += iosize;
2398 /* make sure the mapping tag for page dirty gets cleared */
2399 set_page_writeback(page);
2400 end_page_writeback(page);
2406 /* drop our reference on any cached states */
2407 free_extent_state(cached_state);
2412 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2413 * @mapping: address space structure to write
2414 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2415 * @writepage: function called for each page
2416 * @data: data passed to writepage function
2418 * If a page is already under I/O, write_cache_pages() skips it, even
2419 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2420 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2421 * and msync() need to guarantee that all the data which was dirty at the time
2422 * the call was made get new I/O started against them. If wbc->sync_mode is
2423 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2424 * existing IO to complete.
2426 static int extent_write_cache_pages(struct extent_io_tree *tree,
2427 struct address_space *mapping,
2428 struct writeback_control *wbc,
2429 writepage_t writepage, void *data,
2430 void (*flush_fn)(void *))
2434 int nr_to_write_done = 0;
2435 struct pagevec pvec;
2438 pgoff_t end; /* Inclusive */
2441 pagevec_init(&pvec, 0);
2442 if (wbc->range_cyclic) {
2443 index = mapping->writeback_index; /* Start from prev offset */
2446 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2447 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2451 while (!done && !nr_to_write_done && (index <= end) &&
2452 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
2453 PAGECACHE_TAG_DIRTY, min(end - index,
2454 (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
2458 for (i = 0; i < nr_pages; i++) {
2459 struct page *page = pvec.pages[i];
2462 * At this point we hold neither mapping->tree_lock nor
2463 * lock on the page itself: the page may be truncated or
2464 * invalidated (changing page->mapping to NULL), or even
2465 * swizzled back from swapper_space to tmpfs file
2468 if (tree->ops && tree->ops->write_cache_pages_lock_hook)
2469 tree->ops->write_cache_pages_lock_hook(page);
2473 if (unlikely(page->mapping != mapping)) {
2478 if (!wbc->range_cyclic && page->index > end) {
2484 if (wbc->sync_mode != WB_SYNC_NONE) {
2485 if (PageWriteback(page))
2487 wait_on_page_writeback(page);
2490 if (PageWriteback(page) ||
2491 !clear_page_dirty_for_io(page)) {
2496 ret = (*writepage)(page, wbc, data);
2498 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
2506 * the filesystem may choose to bump up nr_to_write.
2507 * We have to make sure to honor the new nr_to_write
2510 nr_to_write_done = wbc->nr_to_write <= 0;
2512 pagevec_release(&pvec);
2515 if (!scanned && !done) {
2517 * We hit the last page and there is more work to be done: wrap
2518 * back to the start of the file
2527 static void flush_epd_write_bio(struct extent_page_data *epd)
2531 submit_one_bio(WRITE_SYNC, epd->bio, 0, 0);
2533 submit_one_bio(WRITE, epd->bio, 0, 0);
2538 static noinline void flush_write_bio(void *data)
2540 struct extent_page_data *epd = data;
2541 flush_epd_write_bio(epd);
2544 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
2545 get_extent_t *get_extent,
2546 struct writeback_control *wbc)
2549 struct address_space *mapping = page->mapping;
2550 struct extent_page_data epd = {
2553 .get_extent = get_extent,
2555 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
2557 struct writeback_control wbc_writepages = {
2558 .sync_mode = wbc->sync_mode,
2559 .older_than_this = NULL,
2561 .range_start = page_offset(page) + PAGE_CACHE_SIZE,
2562 .range_end = (loff_t)-1,
2565 ret = __extent_writepage(page, wbc, &epd);
2567 extent_write_cache_pages(tree, mapping, &wbc_writepages,
2568 __extent_writepage, &epd, flush_write_bio);
2569 flush_epd_write_bio(&epd);
2573 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
2574 u64 start, u64 end, get_extent_t *get_extent,
2578 struct address_space *mapping = inode->i_mapping;
2580 unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
2583 struct extent_page_data epd = {
2586 .get_extent = get_extent,
2588 .sync_io = mode == WB_SYNC_ALL,
2590 struct writeback_control wbc_writepages = {
2592 .older_than_this = NULL,
2593 .nr_to_write = nr_pages * 2,
2594 .range_start = start,
2595 .range_end = end + 1,
2598 while (start <= end) {
2599 page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
2600 if (clear_page_dirty_for_io(page))
2601 ret = __extent_writepage(page, &wbc_writepages, &epd);
2603 if (tree->ops && tree->ops->writepage_end_io_hook)
2604 tree->ops->writepage_end_io_hook(page, start,
2605 start + PAGE_CACHE_SIZE - 1,
2609 page_cache_release(page);
2610 start += PAGE_CACHE_SIZE;
2613 flush_epd_write_bio(&epd);
2617 int extent_writepages(struct extent_io_tree *tree,
2618 struct address_space *mapping,
2619 get_extent_t *get_extent,
2620 struct writeback_control *wbc)
2623 struct extent_page_data epd = {
2626 .get_extent = get_extent,
2628 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
2631 ret = extent_write_cache_pages(tree, mapping, wbc,
2632 __extent_writepage, &epd,
2634 flush_epd_write_bio(&epd);
2638 int extent_readpages(struct extent_io_tree *tree,
2639 struct address_space *mapping,
2640 struct list_head *pages, unsigned nr_pages,
2641 get_extent_t get_extent)
2643 struct bio *bio = NULL;
2645 unsigned long bio_flags = 0;
2647 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
2648 struct page *page = list_entry(pages->prev, struct page, lru);
2650 prefetchw(&page->flags);
2651 list_del(&page->lru);
2652 if (!add_to_page_cache_lru(page, mapping,
2653 page->index, GFP_KERNEL)) {
2654 __extent_read_full_page(tree, page, get_extent,
2655 &bio, 0, &bio_flags);
2657 page_cache_release(page);
2659 BUG_ON(!list_empty(pages));
2661 submit_one_bio(READ, bio, 0, bio_flags);
2666 * basic invalidatepage code, this waits on any locked or writeback
2667 * ranges corresponding to the page, and then deletes any extent state
2668 * records from the tree
2670 int extent_invalidatepage(struct extent_io_tree *tree,
2671 struct page *page, unsigned long offset)
2673 struct extent_state *cached_state = NULL;
2674 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
2675 u64 end = start + PAGE_CACHE_SIZE - 1;
2676 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
2678 start += (offset + blocksize - 1) & ~(blocksize - 1);
2682 lock_extent_bits(tree, start, end, 0, &cached_state, GFP_NOFS);
2683 wait_on_page_writeback(page);
2684 clear_extent_bit(tree, start, end,
2685 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
2686 EXTENT_DO_ACCOUNTING,
2687 1, 1, &cached_state, GFP_NOFS);
2692 * simple commit_write call, set_range_dirty is used to mark both
2693 * the pages and the extent records as dirty
2695 int extent_commit_write(struct extent_io_tree *tree,
2696 struct inode *inode, struct page *page,
2697 unsigned from, unsigned to)
2699 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
2701 set_page_extent_mapped(page);
2702 set_page_dirty(page);
2704 if (pos > inode->i_size) {
2705 i_size_write(inode, pos);
2706 mark_inode_dirty(inode);
2711 int extent_prepare_write(struct extent_io_tree *tree,
2712 struct inode *inode, struct page *page,
2713 unsigned from, unsigned to, get_extent_t *get_extent)
2715 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2716 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
2718 u64 orig_block_start;
2721 struct extent_map *em;
2722 unsigned blocksize = 1 << inode->i_blkbits;
2723 size_t page_offset = 0;
2724 size_t block_off_start;
2725 size_t block_off_end;
2731 set_page_extent_mapped(page);
2733 block_start = (page_start + from) & ~((u64)blocksize - 1);
2734 block_end = (page_start + to - 1) | (blocksize - 1);
2735 orig_block_start = block_start;
2737 lock_extent(tree, page_start, page_end, GFP_NOFS);
2738 while (block_start <= block_end) {
2739 em = get_extent(inode, page, page_offset, block_start,
2740 block_end - block_start + 1, 1);
2741 if (IS_ERR(em) || !em)
2744 cur_end = min(block_end, extent_map_end(em) - 1);
2745 block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
2746 block_off_end = block_off_start + blocksize;
2747 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);
2749 if (!PageUptodate(page) && isnew &&
2750 (block_off_end > to || block_off_start < from)) {
2753 kaddr = kmap_atomic(page, KM_USER0);
2754 if (block_off_end > to)
2755 memset(kaddr + to, 0, block_off_end - to);
2756 if (block_off_start < from)
2757 memset(kaddr + block_off_start, 0,
2758 from - block_off_start);
2759 flush_dcache_page(page);
2760 kunmap_atomic(kaddr, KM_USER0);
2762 if ((em->block_start != EXTENT_MAP_HOLE &&
2763 em->block_start != EXTENT_MAP_INLINE) &&
2764 !isnew && !PageUptodate(page) &&
2765 (block_off_end > to || block_off_start < from) &&
2766 !test_range_bit(tree, block_start, cur_end,
2767 EXTENT_UPTODATE, 1, NULL)) {
2769 u64 extent_offset = block_start - em->start;
2771 sector = (em->block_start + extent_offset) >> 9;
2772 iosize = (cur_end - block_start + blocksize) &
2773 ~((u64)blocksize - 1);
2775 * we've already got the extent locked, but we
2776 * need to split the state such that our end_bio
2777 * handler can clear the lock.
2779 set_extent_bit(tree, block_start,
2780 block_start + iosize - 1,
2781 EXTENT_LOCKED, 0, NULL, NULL, GFP_NOFS);
2782 ret = submit_extent_page(READ, tree, page,
2783 sector, iosize, page_offset, em->bdev,
2785 end_bio_extent_preparewrite, 0,
2790 block_start = block_start + iosize;
2792 set_extent_uptodate(tree, block_start, cur_end,
2794 unlock_extent(tree, block_start, cur_end, GFP_NOFS);
2795 block_start = cur_end + 1;
2797 page_offset = block_start & (PAGE_CACHE_SIZE - 1);
2798 free_extent_map(em);
2801 wait_extent_bit(tree, orig_block_start,
2802 block_end, EXTENT_LOCKED);
2804 check_page_uptodate(tree, page);
2806 /* FIXME, zero out newly allocated blocks on error */
2811 * a helper for releasepage, this tests for areas of the page that
2812 * are locked or under IO and drops the related state bits if it is safe
2815 int try_release_extent_state(struct extent_map_tree *map,
2816 struct extent_io_tree *tree, struct page *page,
2819 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2820 u64 end = start + PAGE_CACHE_SIZE - 1;
2823 if (test_range_bit(tree, start, end,
2824 EXTENT_IOBITS, 0, NULL))
2827 if ((mask & GFP_NOFS) == GFP_NOFS)
2830 * at this point we can safely clear everything except the
2831 * locked bit and the nodatasum bit
2833 ret = clear_extent_bit(tree, start, end,
2834 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
2837 /* if clear_extent_bit failed for enomem reasons,
2838 * we can't allow the release to continue.
2849 * a helper for releasepage. As long as there are no locked extents
2850 * in the range corresponding to the page, both state records and extent
2851 * map records are removed
2853 int try_release_extent_mapping(struct extent_map_tree *map,
2854 struct extent_io_tree *tree, struct page *page,
2857 struct extent_map *em;
2858 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2859 u64 end = start + PAGE_CACHE_SIZE - 1;
2861 if ((mask & __GFP_WAIT) &&
2862 page->mapping->host->i_size > 16 * 1024 * 1024) {
2864 while (start <= end) {
2865 len = end - start + 1;
2866 write_lock(&map->lock);
2867 em = lookup_extent_mapping(map, start, len);
2868 if (!em || IS_ERR(em)) {
2869 write_unlock(&map->lock);
2872 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
2873 em->start != start) {
2874 write_unlock(&map->lock);
2875 free_extent_map(em);
2878 if (!test_range_bit(tree, em->start,
2879 extent_map_end(em) - 1,
2880 EXTENT_LOCKED | EXTENT_WRITEBACK,
2882 remove_extent_mapping(map, em);
2883 /* once for the rb tree */
2884 free_extent_map(em);
2886 start = extent_map_end(em);
2887 write_unlock(&map->lock);
2890 free_extent_map(em);
2893 return try_release_extent_state(map, tree, page, mask);
2896 sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
2897 get_extent_t *get_extent)
2899 struct inode *inode = mapping->host;
2900 struct extent_state *cached_state = NULL;
2901 u64 start = iblock << inode->i_blkbits;
2902 sector_t sector = 0;
2903 size_t blksize = (1 << inode->i_blkbits);
2904 struct extent_map *em;
2906 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
2907 0, &cached_state, GFP_NOFS);
2908 em = get_extent(inode, NULL, 0, start, blksize, 0);
2909 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start,
2910 start + blksize - 1, &cached_state, GFP_NOFS);
2911 if (!em || IS_ERR(em))
2914 if (em->block_start > EXTENT_MAP_LAST_BYTE)
2917 sector = (em->block_start + start - em->start) >> inode->i_blkbits;
2919 free_extent_map(em);
2924 * helper function for fiemap, which doesn't want to see any holes.
2925 * This maps until we find something past 'last'
2927 static struct extent_map *get_extent_skip_holes(struct inode *inode,
2930 get_extent_t *get_extent)
2932 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
2933 struct extent_map *em;
2940 len = last - offset;
2943 len = (len + sectorsize - 1) & ~(sectorsize - 1);
2944 em = get_extent(inode, NULL, 0, offset, len, 0);
2945 if (!em || IS_ERR(em))
2948 /* if this isn't a hole return it */
2949 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
2950 em->block_start != EXTENT_MAP_HOLE) {
2954 /* this is a hole, advance to the next extent */
2955 offset = extent_map_end(em);
2956 free_extent_map(em);
2963 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2964 __u64 start, __u64 len, get_extent_t *get_extent)
2968 u64 max = start + len;
2972 u64 last_for_get_extent = 0;
2974 u64 isize = i_size_read(inode);
2975 struct btrfs_key found_key;
2976 struct extent_map *em = NULL;
2977 struct extent_state *cached_state = NULL;
2978 struct btrfs_path *path;
2979 struct btrfs_file_extent_item *item;
2984 unsigned long emflags;
2989 path = btrfs_alloc_path();
2992 path->leave_spinning = 1;
2995 * lookup the last file extent. We're not using i_size here
2996 * because there might be preallocation past i_size
2998 ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
2999 path, inode->i_ino, -1, 0);
3001 btrfs_free_path(path);
3006 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3007 struct btrfs_file_extent_item);
3008 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
3009 found_type = btrfs_key_type(&found_key);
3011 /* No extents, but there might be delalloc bits */
3012 if (found_key.objectid != inode->i_ino ||
3013 found_type != BTRFS_EXTENT_DATA_KEY) {
3014 /* have to trust i_size as the end */
3016 last_for_get_extent = isize;
3019 * remember the start of the last extent. There are a
3020 * bunch of different factors that go into the length of the
3021 * extent, so its much less complex to remember where it started
3023 last = found_key.offset;
3024 last_for_get_extent = last + 1;
3026 btrfs_free_path(path);
3029 * we might have some extents allocated but more delalloc past those
3030 * extents. so, we trust isize unless the start of the last extent is
3035 last_for_get_extent = isize;
3038 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
3039 &cached_state, GFP_NOFS);
3041 em = get_extent_skip_holes(inode, off, last_for_get_extent,
3051 u64 offset_in_extent;
3053 /* break if the extent we found is outside the range */
3054 if (em->start >= max || extent_map_end(em) < off)
3058 * get_extent may return an extent that starts before our
3059 * requested range. We have to make sure the ranges
3060 * we return to fiemap always move forward and don't
3061 * overlap, so adjust the offsets here
3063 em_start = max(em->start, off);
3066 * record the offset from the start of the extent
3067 * for adjusting the disk offset below
3069 offset_in_extent = em_start - em->start;
3070 em_end = extent_map_end(em);
3071 em_len = em_end - em_start;
3072 emflags = em->flags;
3077 * bump off for our next call to get_extent
3079 off = extent_map_end(em);
3083 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
3085 flags |= FIEMAP_EXTENT_LAST;
3086 } else if (em->block_start == EXTENT_MAP_INLINE) {
3087 flags |= (FIEMAP_EXTENT_DATA_INLINE |
3088 FIEMAP_EXTENT_NOT_ALIGNED);
3089 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
3090 flags |= (FIEMAP_EXTENT_DELALLOC |
3091 FIEMAP_EXTENT_UNKNOWN);
3093 disko = em->block_start + offset_in_extent;
3095 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
3096 flags |= FIEMAP_EXTENT_ENCODED;
3098 free_extent_map(em);
3100 if ((em_start >= last) || em_len == (u64)-1 ||
3101 (last == (u64)-1 && isize <= em_end)) {
3102 flags |= FIEMAP_EXTENT_LAST;
3106 /* now scan forward to see if this is really the last extent. */
3107 em = get_extent_skip_holes(inode, off, last_for_get_extent,
3114 flags |= FIEMAP_EXTENT_LAST;
3117 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
3123 free_extent_map(em);
3125 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len,
3126 &cached_state, GFP_NOFS);
3130 static inline struct page *extent_buffer_page(struct extent_buffer *eb,
3134 struct address_space *mapping;
3137 return eb->first_page;
3138 i += eb->start >> PAGE_CACHE_SHIFT;
3139 mapping = eb->first_page->mapping;
3144 * extent_buffer_page is only called after pinning the page
3145 * by increasing the reference count. So we know the page must
3146 * be in the radix tree.
3149 p = radix_tree_lookup(&mapping->page_tree, i);
3155 static inline unsigned long num_extent_pages(u64 start, u64 len)
3157 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
3158 (start >> PAGE_CACHE_SHIFT);
3161 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
3166 struct extent_buffer *eb = NULL;
3168 unsigned long flags;
3171 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
3176 spin_lock_init(&eb->lock);
3177 init_waitqueue_head(&eb->lock_wq);
3180 spin_lock_irqsave(&leak_lock, flags);
3181 list_add(&eb->leak_list, &buffers);
3182 spin_unlock_irqrestore(&leak_lock, flags);
3184 atomic_set(&eb->refs, 1);
3189 static void __free_extent_buffer(struct extent_buffer *eb)
3192 unsigned long flags;
3193 spin_lock_irqsave(&leak_lock, flags);
3194 list_del(&eb->leak_list);
3195 spin_unlock_irqrestore(&leak_lock, flags);
3197 kmem_cache_free(extent_buffer_cache, eb);
3201 * Helper for releasing extent buffer page.
3203 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
3204 unsigned long start_idx)
3206 unsigned long index;
3209 if (!eb->first_page)
3212 index = num_extent_pages(eb->start, eb->len);
3213 if (start_idx >= index)
3218 page = extent_buffer_page(eb, index);
3220 page_cache_release(page);
3221 } while (index != start_idx);
3225 * Helper for releasing the extent buffer.
3227 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
3229 btrfs_release_extent_buffer_page(eb, 0);
3230 __free_extent_buffer(eb);
3233 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
3234 u64 start, unsigned long len,
3238 unsigned long num_pages = num_extent_pages(start, len);
3240 unsigned long index = start >> PAGE_CACHE_SHIFT;
3241 struct extent_buffer *eb;
3242 struct extent_buffer *exists = NULL;
3244 struct address_space *mapping = tree->mapping;
3249 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3250 if (eb && atomic_inc_not_zero(&eb->refs)) {
3252 mark_page_accessed(eb->first_page);
3257 eb = __alloc_extent_buffer(tree, start, len, mask);
3262 eb->first_page = page0;
3265 page_cache_get(page0);
3266 mark_page_accessed(page0);
3267 set_page_extent_mapped(page0);
3268 set_page_extent_head(page0, len);
3269 uptodate = PageUptodate(page0);
3273 for (; i < num_pages; i++, index++) {
3274 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
3279 set_page_extent_mapped(p);
3280 mark_page_accessed(p);
3283 set_page_extent_head(p, len);
3285 set_page_private(p, EXTENT_PAGE_PRIVATE);
3287 if (!PageUptodate(p))
3291 * see below about how we avoid a nasty race with release page
3292 * and why we unlock later
3298 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3300 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
3304 spin_lock(&tree->buffer_lock);
3305 ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
3306 if (ret == -EEXIST) {
3307 exists = radix_tree_lookup(&tree->buffer,
3308 start >> PAGE_CACHE_SHIFT);
3309 /* add one reference for the caller */
3310 atomic_inc(&exists->refs);
3311 spin_unlock(&tree->buffer_lock);
3312 radix_tree_preload_end();
3315 /* add one reference for the tree */
3316 atomic_inc(&eb->refs);
3317 spin_unlock(&tree->buffer_lock);
3318 radix_tree_preload_end();
3321 * there is a race where release page may have
3322 * tried to find this extent buffer in the radix
3323 * but failed. It will tell the VM it is safe to
3324 * reclaim the, and it will clear the page private bit.
3325 * We must make sure to set the page private bit properly
3326 * after the extent buffer is in the radix tree so
3327 * it doesn't get lost
3329 set_page_extent_mapped(eb->first_page);
3330 set_page_extent_head(eb->first_page, eb->len);
3332 unlock_page(eb->first_page);
3336 if (eb->first_page && !page0)
3337 unlock_page(eb->first_page);
3339 if (!atomic_dec_and_test(&eb->refs))
3341 btrfs_release_extent_buffer(eb);
3345 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
3346 u64 start, unsigned long len,
3349 struct extent_buffer *eb;
3352 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3353 if (eb && atomic_inc_not_zero(&eb->refs)) {
3355 mark_page_accessed(eb->first_page);
3363 void free_extent_buffer(struct extent_buffer *eb)
3368 if (!atomic_dec_and_test(&eb->refs))
3374 int clear_extent_buffer_dirty(struct extent_io_tree *tree,
3375 struct extent_buffer *eb)
3378 unsigned long num_pages;
3381 num_pages = num_extent_pages(eb->start, eb->len);
3383 for (i = 0; i < num_pages; i++) {
3384 page = extent_buffer_page(eb, i);
3385 if (!PageDirty(page))
3389 WARN_ON(!PagePrivate(page));
3391 set_page_extent_mapped(page);
3393 set_page_extent_head(page, eb->len);
3395 clear_page_dirty_for_io(page);
3396 spin_lock_irq(&page->mapping->tree_lock);
3397 if (!PageDirty(page)) {
3398 radix_tree_tag_clear(&page->mapping->page_tree,
3400 PAGECACHE_TAG_DIRTY);
3402 spin_unlock_irq(&page->mapping->tree_lock);
3408 int wait_on_extent_buffer_writeback(struct extent_io_tree *tree,
3409 struct extent_buffer *eb)
3411 return wait_on_extent_writeback(tree, eb->start,
3412 eb->start + eb->len - 1);
3415 int set_extent_buffer_dirty(struct extent_io_tree *tree,
3416 struct extent_buffer *eb)
3419 unsigned long num_pages;
3422 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
3423 num_pages = num_extent_pages(eb->start, eb->len);
3424 for (i = 0; i < num_pages; i++)
3425 __set_page_dirty_nobuffers(extent_buffer_page(eb, i));
3429 int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
3430 struct extent_buffer *eb,
3431 struct extent_state **cached_state)
3435 unsigned long num_pages;
3437 num_pages = num_extent_pages(eb->start, eb->len);
3438 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3440 clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3441 cached_state, GFP_NOFS);
3442 for (i = 0; i < num_pages; i++) {
3443 page = extent_buffer_page(eb, i);
3445 ClearPageUptodate(page);
3450 int set_extent_buffer_uptodate(struct extent_io_tree *tree,
3451 struct extent_buffer *eb)
3455 unsigned long num_pages;
3457 num_pages = num_extent_pages(eb->start, eb->len);
3459 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3461 for (i = 0; i < num_pages; i++) {
3462 page = extent_buffer_page(eb, i);
3463 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
3464 ((i == num_pages - 1) &&
3465 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
3466 check_page_uptodate(tree, page);
3469 SetPageUptodate(page);
3474 int extent_range_uptodate(struct extent_io_tree *tree,
3479 int pg_uptodate = 1;
3481 unsigned long index;
3483 ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL);
3486 while (start <= end) {
3487 index = start >> PAGE_CACHE_SHIFT;
3488 page = find_get_page(tree->mapping, index);
3489 uptodate = PageUptodate(page);
3490 page_cache_release(page);
3495 start += PAGE_CACHE_SIZE;
3500 int extent_buffer_uptodate(struct extent_io_tree *tree,
3501 struct extent_buffer *eb,
3502 struct extent_state *cached_state)
3505 unsigned long num_pages;
3508 int pg_uptodate = 1;
3510 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3513 ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3514 EXTENT_UPTODATE, 1, cached_state);
3518 num_pages = num_extent_pages(eb->start, eb->len);
3519 for (i = 0; i < num_pages; i++) {
3520 page = extent_buffer_page(eb, i);
3521 if (!PageUptodate(page)) {
3529 int read_extent_buffer_pages(struct extent_io_tree *tree,
3530 struct extent_buffer *eb,
3531 u64 start, int wait,
3532 get_extent_t *get_extent, int mirror_num)
3535 unsigned long start_i;
3539 int locked_pages = 0;
3540 int all_uptodate = 1;
3541 int inc_all_pages = 0;
3542 unsigned long num_pages;
3543 struct bio *bio = NULL;
3544 unsigned long bio_flags = 0;
3546 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3549 if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3550 EXTENT_UPTODATE, 1, NULL)) {
3555 WARN_ON(start < eb->start);
3556 start_i = (start >> PAGE_CACHE_SHIFT) -
3557 (eb->start >> PAGE_CACHE_SHIFT);
3562 num_pages = num_extent_pages(eb->start, eb->len);
3563 for (i = start_i; i < num_pages; i++) {
3564 page = extent_buffer_page(eb, i);
3566 if (!trylock_page(page))
3572 if (!PageUptodate(page))
3577 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3581 for (i = start_i; i < num_pages; i++) {
3582 page = extent_buffer_page(eb, i);
3584 WARN_ON(!PagePrivate(page));
3586 set_page_extent_mapped(page);
3588 set_page_extent_head(page, eb->len);
3591 page_cache_get(page);
3592 if (!PageUptodate(page)) {
3595 ClearPageError(page);
3596 err = __extent_read_full_page(tree, page,
3598 mirror_num, &bio_flags);
3607 submit_one_bio(READ, bio, mirror_num, bio_flags);
3612 for (i = start_i; i < num_pages; i++) {
3613 page = extent_buffer_page(eb, i);
3614 wait_on_page_locked(page);
3615 if (!PageUptodate(page))
3620 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3625 while (locked_pages > 0) {
3626 page = extent_buffer_page(eb, i);
3634 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
3635 unsigned long start,
3642 char *dst = (char *)dstv;
3643 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3644 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3646 WARN_ON(start > eb->len);
3647 WARN_ON(start + len > eb->start + eb->len);
3649 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3652 page = extent_buffer_page(eb, i);
3654 cur = min(len, (PAGE_CACHE_SIZE - offset));
3655 kaddr = kmap_atomic(page, KM_USER1);
3656 memcpy(dst, kaddr + offset, cur);
3657 kunmap_atomic(kaddr, KM_USER1);
3666 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
3667 unsigned long min_len, char **token, char **map,
3668 unsigned long *map_start,
3669 unsigned long *map_len, int km)
3671 size_t offset = start & (PAGE_CACHE_SIZE - 1);
3674 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3675 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3676 unsigned long end_i = (start_offset + start + min_len - 1) >>
3683 offset = start_offset;
3687 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
3690 if (start + min_len > eb->len) {
3691 printk(KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
3692 "wanted %lu %lu\n", (unsigned long long)eb->start,
3693 eb->len, start, min_len);
3698 p = extent_buffer_page(eb, i);
3699 kaddr = kmap_atomic(p, km);
3701 *map = kaddr + offset;
3702 *map_len = PAGE_CACHE_SIZE - offset;
3706 int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
3707 unsigned long min_len,
3708 char **token, char **map,
3709 unsigned long *map_start,
3710 unsigned long *map_len, int km)
3714 if (eb->map_token) {
3715 unmap_extent_buffer(eb, eb->map_token, km);
3716 eb->map_token = NULL;
3719 err = map_private_extent_buffer(eb, start, min_len, token, map,
3720 map_start, map_len, km);
3722 eb->map_token = *token;
3724 eb->map_start = *map_start;
3725 eb->map_len = *map_len;
3730 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)
3732 kunmap_atomic(token, km);
3735 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
3736 unsigned long start,
3743 char *ptr = (char *)ptrv;
3744 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3745 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3748 WARN_ON(start > eb->len);
3749 WARN_ON(start + len > eb->start + eb->len);
3751 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3754 page = extent_buffer_page(eb, i);
3756 cur = min(len, (PAGE_CACHE_SIZE - offset));
3758 kaddr = kmap_atomic(page, KM_USER0);
3759 ret = memcmp(ptr, kaddr + offset, cur);
3760 kunmap_atomic(kaddr, KM_USER0);
3772 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
3773 unsigned long start, unsigned long len)
3779 char *src = (char *)srcv;
3780 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3781 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);
3790 WARN_ON(!PageUptodate(page));
3792 cur = min(len, PAGE_CACHE_SIZE - offset);
3793 kaddr = kmap_atomic(page, KM_USER1);
3794 memcpy(kaddr + offset, src, cur);
3795 kunmap_atomic(kaddr, KM_USER1);
3804 void memset_extent_buffer(struct extent_buffer *eb, char c,
3805 unsigned long start, unsigned long len)
3811 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3812 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3814 WARN_ON(start > eb->len);
3815 WARN_ON(start + len > eb->start + eb->len);
3817 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3820 page = extent_buffer_page(eb, i);
3821 WARN_ON(!PageUptodate(page));
3823 cur = min(len, PAGE_CACHE_SIZE - offset);
3824 kaddr = kmap_atomic(page, KM_USER0);
3825 memset(kaddr + offset, c, cur);
3826 kunmap_atomic(kaddr, KM_USER0);
3834 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
3835 unsigned long dst_offset, unsigned long src_offset,
3838 u64 dst_len = dst->len;
3843 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3844 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3846 WARN_ON(src->len != dst_len);
3848 offset = (start_offset + dst_offset) &
3849 ((unsigned long)PAGE_CACHE_SIZE - 1);
3852 page = extent_buffer_page(dst, i);
3853 WARN_ON(!PageUptodate(page));
3855 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
3857 kaddr = kmap_atomic(page, KM_USER0);
3858 read_extent_buffer(src, kaddr + offset, src_offset, cur);
3859 kunmap_atomic(kaddr, KM_USER0);
3868 static void move_pages(struct page *dst_page, struct page *src_page,
3869 unsigned long dst_off, unsigned long src_off,
3872 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3873 if (dst_page == src_page) {
3874 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
3876 char *src_kaddr = kmap_atomic(src_page, KM_USER1);
3877 char *p = dst_kaddr + dst_off + len;
3878 char *s = src_kaddr + src_off + len;
3883 kunmap_atomic(src_kaddr, KM_USER1);
3885 kunmap_atomic(dst_kaddr, KM_USER0);
3888 static void copy_pages(struct page *dst_page, struct page *src_page,
3889 unsigned long dst_off, unsigned long src_off,
3892 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3895 if (dst_page != src_page)
3896 src_kaddr = kmap_atomic(src_page, KM_USER1);
3898 src_kaddr = dst_kaddr;
3900 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
3901 kunmap_atomic(dst_kaddr, KM_USER0);
3902 if (dst_page != src_page)
3903 kunmap_atomic(src_kaddr, KM_USER1);
3906 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3907 unsigned long src_offset, unsigned long len)
3910 size_t dst_off_in_page;
3911 size_t src_off_in_page;
3912 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3913 unsigned long dst_i;
3914 unsigned long src_i;
3916 if (src_offset + len > dst->len) {
3917 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
3918 "len %lu dst len %lu\n", src_offset, len, dst->len);
3921 if (dst_offset + len > dst->len) {
3922 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
3923 "len %lu dst len %lu\n", dst_offset, len, dst->len);
3928 dst_off_in_page = (start_offset + dst_offset) &
3929 ((unsigned long)PAGE_CACHE_SIZE - 1);
3930 src_off_in_page = (start_offset + src_offset) &
3931 ((unsigned long)PAGE_CACHE_SIZE - 1);
3933 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3934 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
3936 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
3938 cur = min_t(unsigned long, cur,
3939 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
3941 copy_pages(extent_buffer_page(dst, dst_i),
3942 extent_buffer_page(dst, src_i),
3943 dst_off_in_page, src_off_in_page, cur);
3951 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3952 unsigned long src_offset, unsigned long len)
3955 size_t dst_off_in_page;
3956 size_t src_off_in_page;
3957 unsigned long dst_end = dst_offset + len - 1;
3958 unsigned long src_end = src_offset + len - 1;
3959 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3960 unsigned long dst_i;
3961 unsigned long src_i;
3963 if (src_offset + len > dst->len) {
3964 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
3965 "len %lu len %lu\n", src_offset, len, dst->len);
3968 if (dst_offset + len > dst->len) {
3969 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
3970 "len %lu len %lu\n", dst_offset, len, dst->len);
3973 if (dst_offset < src_offset) {
3974 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
3978 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
3979 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
3981 dst_off_in_page = (start_offset + dst_end) &
3982 ((unsigned long)PAGE_CACHE_SIZE - 1);
3983 src_off_in_page = (start_offset + src_end) &
3984 ((unsigned long)PAGE_CACHE_SIZE - 1);
3986 cur = min_t(unsigned long, len, src_off_in_page + 1);
3987 cur = min(cur, dst_off_in_page + 1);
3988 move_pages(extent_buffer_page(dst, dst_i),
3989 extent_buffer_page(dst, src_i),
3990 dst_off_in_page - cur + 1,
3991 src_off_in_page - cur + 1, cur);
3999 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
4001 struct extent_buffer *eb =
4002 container_of(head, struct extent_buffer, rcu_head);
4004 btrfs_release_extent_buffer(eb);
4007 int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
4009 u64 start = page_offset(page);
4010 struct extent_buffer *eb;
4013 spin_lock(&tree->buffer_lock);
4014 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4016 spin_unlock(&tree->buffer_lock);
4020 if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
4026 * set @eb->refs to 0 if it is already 1, and then release the @eb.
4029 if (atomic_cmpxchg(&eb->refs, 1, 0) != 1) {
4034 radix_tree_delete(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4036 spin_unlock(&tree->buffer_lock);
4038 /* at this point we can safely release the extent buffer */
4039 if (atomic_read(&eb->refs) == 0)
4040 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);