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 <linux/cleancache.h>
15 #include "extent_io.h"
16 #include "extent_map.h"
19 #include "btrfs_inode.h"
21 static struct kmem_cache *extent_state_cache;
22 static struct kmem_cache *extent_buffer_cache;
24 static LIST_HEAD(buffers);
25 static LIST_HEAD(states);
29 static DEFINE_SPINLOCK(leak_lock);
32 #define BUFFER_LRU_MAX 64
37 struct rb_node rb_node;
40 struct extent_page_data {
42 struct extent_io_tree *tree;
43 get_extent_t *get_extent;
45 /* tells writepage not to lock the state bits for this range
46 * it still does the unlocking
48 unsigned int extent_locked:1;
50 /* tells the submit_bio code to use a WRITE_SYNC */
51 unsigned int sync_io:1;
54 int __init extent_io_init(void)
56 extent_state_cache = kmem_cache_create("extent_state",
57 sizeof(struct extent_state), 0,
58 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
59 if (!extent_state_cache)
62 extent_buffer_cache = kmem_cache_create("extent_buffers",
63 sizeof(struct extent_buffer), 0,
64 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
65 if (!extent_buffer_cache)
66 goto free_state_cache;
70 kmem_cache_destroy(extent_state_cache);
74 void extent_io_exit(void)
76 struct extent_state *state;
77 struct extent_buffer *eb;
79 while (!list_empty(&states)) {
80 state = list_entry(states.next, struct extent_state, leak_list);
81 printk(KERN_ERR "btrfs state leak: start %llu end %llu "
82 "state %lu in tree %p refs %d\n",
83 (unsigned long long)state->start,
84 (unsigned long long)state->end,
85 state->state, state->tree, atomic_read(&state->refs));
86 list_del(&state->leak_list);
87 kmem_cache_free(extent_state_cache, state);
91 while (!list_empty(&buffers)) {
92 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
93 printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
94 "refs %d\n", (unsigned long long)eb->start,
95 eb->len, atomic_read(&eb->refs));
96 list_del(&eb->leak_list);
97 kmem_cache_free(extent_buffer_cache, eb);
99 if (extent_state_cache)
100 kmem_cache_destroy(extent_state_cache);
101 if (extent_buffer_cache)
102 kmem_cache_destroy(extent_buffer_cache);
105 void extent_io_tree_init(struct extent_io_tree *tree,
106 struct address_space *mapping)
108 tree->state = RB_ROOT;
109 INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
111 tree->dirty_bytes = 0;
112 spin_lock_init(&tree->lock);
113 spin_lock_init(&tree->buffer_lock);
114 tree->mapping = mapping;
117 static struct extent_state *alloc_extent_state(gfp_t mask)
119 struct extent_state *state;
124 state = kmem_cache_alloc(extent_state_cache, mask);
131 spin_lock_irqsave(&leak_lock, flags);
132 list_add(&state->leak_list, &states);
133 spin_unlock_irqrestore(&leak_lock, flags);
135 atomic_set(&state->refs, 1);
136 init_waitqueue_head(&state->wq);
140 void free_extent_state(struct extent_state *state)
144 if (atomic_dec_and_test(&state->refs)) {
148 WARN_ON(state->tree);
150 spin_lock_irqsave(&leak_lock, flags);
151 list_del(&state->leak_list);
152 spin_unlock_irqrestore(&leak_lock, flags);
154 kmem_cache_free(extent_state_cache, state);
158 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
159 struct rb_node *node)
161 struct rb_node **p = &root->rb_node;
162 struct rb_node *parent = NULL;
163 struct tree_entry *entry;
167 entry = rb_entry(parent, struct tree_entry, rb_node);
169 if (offset < entry->start)
171 else if (offset > entry->end)
177 entry = rb_entry(node, struct tree_entry, rb_node);
178 rb_link_node(node, parent, p);
179 rb_insert_color(node, root);
183 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
184 struct rb_node **prev_ret,
185 struct rb_node **next_ret)
187 struct rb_root *root = &tree->state;
188 struct rb_node *n = root->rb_node;
189 struct rb_node *prev = NULL;
190 struct rb_node *orig_prev = NULL;
191 struct tree_entry *entry;
192 struct tree_entry *prev_entry = NULL;
195 entry = rb_entry(n, struct tree_entry, rb_node);
199 if (offset < entry->start)
201 else if (offset > entry->end)
209 while (prev && offset > prev_entry->end) {
210 prev = rb_next(prev);
211 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
218 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
219 while (prev && offset < prev_entry->start) {
220 prev = rb_prev(prev);
221 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
228 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
231 struct rb_node *prev = NULL;
234 ret = __etree_search(tree, offset, &prev, NULL);
240 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
241 struct extent_state *other)
243 if (tree->ops && tree->ops->merge_extent_hook)
244 tree->ops->merge_extent_hook(tree->mapping->host, new,
249 * utility function to look for merge candidates inside a given range.
250 * Any extents with matching state are merged together into a single
251 * extent in the tree. Extents with EXTENT_IO in their state field
252 * are not merged because the end_io handlers need to be able to do
253 * operations on them without sleeping (or doing allocations/splits).
255 * This should be called with the tree lock held.
257 static int merge_state(struct extent_io_tree *tree,
258 struct extent_state *state)
260 struct extent_state *other;
261 struct rb_node *other_node;
263 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
266 other_node = rb_prev(&state->rb_node);
268 other = rb_entry(other_node, struct extent_state, rb_node);
269 if (other->end == state->start - 1 &&
270 other->state == state->state) {
271 merge_cb(tree, state, other);
272 state->start = other->start;
274 rb_erase(&other->rb_node, &tree->state);
275 free_extent_state(other);
278 other_node = rb_next(&state->rb_node);
280 other = rb_entry(other_node, struct extent_state, rb_node);
281 if (other->start == state->end + 1 &&
282 other->state == state->state) {
283 merge_cb(tree, state, other);
284 state->end = other->end;
286 rb_erase(&other->rb_node, &tree->state);
287 free_extent_state(other);
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);
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);
442 static struct extent_state *
443 alloc_extent_state_atomic(struct extent_state *prealloc)
446 prealloc = alloc_extent_state(GFP_ATOMIC);
452 * clear some bits on a range in the tree. This may require splitting
453 * or inserting elements in the tree, so the gfp mask is used to
454 * indicate which allocations or sleeping are allowed.
456 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
457 * the given range from the tree regardless of state (ie for truncate).
459 * the range [start, end] is inclusive.
461 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
462 * bits were already set, or zero if none of the bits were already set.
464 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
465 int bits, int wake, int delete,
466 struct extent_state **cached_state,
469 struct extent_state *state;
470 struct extent_state *cached;
471 struct extent_state *prealloc = NULL;
472 struct rb_node *next_node;
473 struct rb_node *node;
480 bits |= ~EXTENT_CTLBITS;
481 bits |= EXTENT_FIRST_DELALLOC;
483 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
486 if (!prealloc && (mask & __GFP_WAIT)) {
487 prealloc = alloc_extent_state(mask);
492 spin_lock(&tree->lock);
494 cached = *cached_state;
497 *cached_state = NULL;
501 if (cached && cached->tree && cached->start <= start &&
502 cached->end > start) {
504 atomic_dec(&cached->refs);
509 free_extent_state(cached);
512 * this search will find the extents that end after
515 node = tree_search(tree, start);
518 state = rb_entry(node, struct extent_state, rb_node);
520 if (state->start > end)
522 WARN_ON(state->end < start);
523 last_end = state->end;
526 * | ---- desired range ---- |
528 * | ------------- state -------------- |
530 * We need to split the extent we found, and may flip
531 * bits on second half.
533 * If the extent we found extends past our range, we
534 * just split and search again. It'll get split again
535 * the next time though.
537 * If the extent we found is inside our range, we clear
538 * the desired bit on it.
541 if (state->start < start) {
542 prealloc = alloc_extent_state_atomic(prealloc);
544 err = split_state(tree, state, prealloc, start);
545 BUG_ON(err == -EEXIST);
549 if (state->end <= end) {
550 set |= clear_state_bit(tree, state, &bits, wake);
551 if (last_end == (u64)-1)
553 start = last_end + 1;
558 * | ---- desired range ---- |
560 * We need to split the extent, and clear the bit
563 if (state->start <= end && state->end > end) {
564 prealloc = alloc_extent_state_atomic(prealloc);
566 err = split_state(tree, state, prealloc, end + 1);
567 BUG_ON(err == -EEXIST);
571 set |= clear_state_bit(tree, prealloc, &bits, wake);
577 if (state->end < end && prealloc && !need_resched())
578 next_node = rb_next(&state->rb_node);
582 set |= clear_state_bit(tree, state, &bits, wake);
583 if (last_end == (u64)-1)
585 start = last_end + 1;
586 if (start <= end && next_node) {
587 state = rb_entry(next_node, struct extent_state,
589 if (state->start == start)
595 spin_unlock(&tree->lock);
597 free_extent_state(prealloc);
604 spin_unlock(&tree->lock);
605 if (mask & __GFP_WAIT)
610 static int wait_on_state(struct extent_io_tree *tree,
611 struct extent_state *state)
612 __releases(tree->lock)
613 __acquires(tree->lock)
616 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
617 spin_unlock(&tree->lock);
619 spin_lock(&tree->lock);
620 finish_wait(&state->wq, &wait);
625 * waits for one or more bits to clear on a range in the state tree.
626 * The range [start, end] is inclusive.
627 * The tree lock is taken by this function
629 int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
631 struct extent_state *state;
632 struct rb_node *node;
634 spin_lock(&tree->lock);
638 * this search will find all the extents that end after
641 node = tree_search(tree, start);
645 state = rb_entry(node, struct extent_state, rb_node);
647 if (state->start > end)
650 if (state->state & bits) {
651 start = state->start;
652 atomic_inc(&state->refs);
653 wait_on_state(tree, state);
654 free_extent_state(state);
657 start = state->end + 1;
662 if (need_resched()) {
663 spin_unlock(&tree->lock);
665 spin_lock(&tree->lock);
669 spin_unlock(&tree->lock);
673 static int set_state_bits(struct extent_io_tree *tree,
674 struct extent_state *state,
678 int bits_to_set = *bits & ~EXTENT_CTLBITS;
680 ret = set_state_cb(tree, state, bits);
683 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
684 u64 range = state->end - state->start + 1;
685 tree->dirty_bytes += range;
687 state->state |= bits_to_set;
692 static void cache_state(struct extent_state *state,
693 struct extent_state **cached_ptr)
695 if (cached_ptr && !(*cached_ptr)) {
696 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
698 atomic_inc(&state->refs);
703 static void uncache_state(struct extent_state **cached_ptr)
705 if (cached_ptr && (*cached_ptr)) {
706 struct extent_state *state = *cached_ptr;
708 free_extent_state(state);
713 * set some bits on a range in the tree. This may require allocations or
714 * sleeping, so the gfp mask is used to indicate what is allowed.
716 * If any of the exclusive bits are set, this will fail with -EEXIST if some
717 * part of the range already has the desired bits set. The start of the
718 * existing range is returned in failed_start in this case.
720 * [start, end] is inclusive This takes the tree lock.
723 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
724 int bits, int exclusive_bits, u64 *failed_start,
725 struct extent_state **cached_state, gfp_t mask)
727 struct extent_state *state;
728 struct extent_state *prealloc = NULL;
729 struct rb_node *node;
734 bits |= EXTENT_FIRST_DELALLOC;
736 if (!prealloc && (mask & __GFP_WAIT)) {
737 prealloc = alloc_extent_state(mask);
741 spin_lock(&tree->lock);
742 if (cached_state && *cached_state) {
743 state = *cached_state;
744 if (state->start <= start && state->end > start &&
746 node = &state->rb_node;
751 * this search will find all the extents that end after
754 node = tree_search(tree, start);
756 prealloc = alloc_extent_state_atomic(prealloc);
758 err = insert_state(tree, prealloc, start, end, &bits);
760 BUG_ON(err == -EEXIST);
763 state = rb_entry(node, struct extent_state, rb_node);
765 last_start = state->start;
766 last_end = state->end;
769 * | ---- desired range ---- |
772 * Just lock what we found and keep going
774 if (state->start == start && state->end <= end) {
775 struct rb_node *next_node;
776 if (state->state & exclusive_bits) {
777 *failed_start = state->start;
782 err = set_state_bits(tree, state, &bits);
786 cache_state(state, cached_state);
787 merge_state(tree, state);
788 if (last_end == (u64)-1)
791 start = last_end + 1;
792 next_node = rb_next(&state->rb_node);
793 if (next_node && start < end && prealloc && !need_resched()) {
794 state = rb_entry(next_node, struct extent_state,
796 if (state->start == start)
803 * | ---- desired range ---- |
806 * | ------------- state -------------- |
808 * We need to split the extent we found, and may flip bits on
811 * If the extent we found extends past our
812 * range, we just split and search again. It'll get split
813 * again the next time though.
815 * If the extent we found is inside our range, we set the
818 if (state->start < start) {
819 if (state->state & exclusive_bits) {
820 *failed_start = start;
825 prealloc = alloc_extent_state_atomic(prealloc);
827 err = split_state(tree, state, prealloc, start);
828 BUG_ON(err == -EEXIST);
832 if (state->end <= end) {
833 err = set_state_bits(tree, state, &bits);
836 cache_state(state, cached_state);
837 merge_state(tree, state);
838 if (last_end == (u64)-1)
840 start = last_end + 1;
845 * | ---- desired range ---- |
846 * | state | or | state |
848 * There's a hole, we need to insert something in it and
849 * ignore the extent we found.
851 if (state->start > start) {
853 if (end < last_start)
856 this_end = last_start - 1;
858 prealloc = alloc_extent_state_atomic(prealloc);
862 * Avoid to free 'prealloc' if it can be merged with
865 err = insert_state(tree, prealloc, start, this_end,
867 BUG_ON(err == -EEXIST);
869 free_extent_state(prealloc);
873 cache_state(prealloc, cached_state);
875 start = this_end + 1;
879 * | ---- desired range ---- |
881 * We need to split the extent, and set the bit
884 if (state->start <= end && state->end > end) {
885 if (state->state & exclusive_bits) {
886 *failed_start = start;
891 prealloc = alloc_extent_state_atomic(prealloc);
893 err = split_state(tree, state, prealloc, end + 1);
894 BUG_ON(err == -EEXIST);
896 err = set_state_bits(tree, prealloc, &bits);
901 cache_state(prealloc, cached_state);
902 merge_state(tree, prealloc);
910 spin_unlock(&tree->lock);
912 free_extent_state(prealloc);
919 spin_unlock(&tree->lock);
920 if (mask & __GFP_WAIT)
925 /* wrappers around set/clear extent bit */
926 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
929 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
933 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
934 int bits, gfp_t mask)
936 return set_extent_bit(tree, start, end, bits, 0, NULL,
940 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
941 int bits, gfp_t mask)
943 return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
946 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
947 struct extent_state **cached_state, gfp_t mask)
949 return set_extent_bit(tree, start, end,
950 EXTENT_DELALLOC | EXTENT_DIRTY | EXTENT_UPTODATE,
951 0, NULL, cached_state, mask);
954 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
957 return clear_extent_bit(tree, start, end,
958 EXTENT_DIRTY | EXTENT_DELALLOC |
959 EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
962 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
965 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
969 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
970 struct extent_state **cached_state, gfp_t mask)
972 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0,
973 NULL, cached_state, mask);
976 static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
977 u64 end, struct extent_state **cached_state,
980 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
985 * either insert or lock state struct between start and end use mask to tell
986 * us if waiting is desired.
988 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
989 int bits, struct extent_state **cached_state, gfp_t mask)
994 err = set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
995 EXTENT_LOCKED, &failed_start,
997 if (err == -EEXIST && (mask & __GFP_WAIT)) {
998 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
999 start = failed_start;
1003 WARN_ON(start > end);
1008 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
1010 return lock_extent_bits(tree, start, end, 0, NULL, mask);
1013 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
1019 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1020 &failed_start, NULL, mask);
1021 if (err == -EEXIST) {
1022 if (failed_start > start)
1023 clear_extent_bit(tree, start, failed_start - 1,
1024 EXTENT_LOCKED, 1, 0, NULL, mask);
1030 int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
1031 struct extent_state **cached, gfp_t mask)
1033 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
1037 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
1039 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
1044 * helper function to set both pages and extents in the tree writeback
1046 static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1048 unsigned long index = start >> PAGE_CACHE_SHIFT;
1049 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1052 while (index <= end_index) {
1053 page = find_get_page(tree->mapping, index);
1055 set_page_writeback(page);
1056 page_cache_release(page);
1063 * find the first offset in the io tree with 'bits' set. zero is
1064 * returned if we find something, and *start_ret and *end_ret are
1065 * set to reflect the state struct that was found.
1067 * If nothing was found, 1 is returned, < 0 on error
1069 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1070 u64 *start_ret, u64 *end_ret, int bits)
1072 struct rb_node *node;
1073 struct extent_state *state;
1076 spin_lock(&tree->lock);
1078 * this search will find all the extents that end after
1081 node = tree_search(tree, start);
1086 state = rb_entry(node, struct extent_state, rb_node);
1087 if (state->end >= start && (state->state & bits)) {
1088 *start_ret = state->start;
1089 *end_ret = state->end;
1093 node = rb_next(node);
1098 spin_unlock(&tree->lock);
1102 /* find the first state struct with 'bits' set after 'start', and
1103 * return it. tree->lock must be held. NULL will returned if
1104 * nothing was found after 'start'
1106 struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
1107 u64 start, int bits)
1109 struct rb_node *node;
1110 struct extent_state *state;
1113 * this search will find all the extents that end after
1116 node = tree_search(tree, start);
1121 state = rb_entry(node, struct extent_state, rb_node);
1122 if (state->end >= start && (state->state & bits))
1125 node = rb_next(node);
1134 * find a contiguous range of bytes in the file marked as delalloc, not
1135 * more than 'max_bytes'. start and end are used to return the range,
1137 * 1 is returned if we find something, 0 if nothing was in the tree
1139 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1140 u64 *start, u64 *end, u64 max_bytes,
1141 struct extent_state **cached_state)
1143 struct rb_node *node;
1144 struct extent_state *state;
1145 u64 cur_start = *start;
1147 u64 total_bytes = 0;
1149 spin_lock(&tree->lock);
1152 * this search will find all the extents that end after
1155 node = tree_search(tree, cur_start);
1163 state = rb_entry(node, struct extent_state, rb_node);
1164 if (found && (state->start != cur_start ||
1165 (state->state & EXTENT_BOUNDARY))) {
1168 if (!(state->state & EXTENT_DELALLOC)) {
1174 *start = state->start;
1175 *cached_state = state;
1176 atomic_inc(&state->refs);
1180 cur_start = state->end + 1;
1181 node = rb_next(node);
1184 total_bytes += state->end - state->start + 1;
1185 if (total_bytes >= max_bytes)
1189 spin_unlock(&tree->lock);
1193 static noinline int __unlock_for_delalloc(struct inode *inode,
1194 struct page *locked_page,
1198 struct page *pages[16];
1199 unsigned long index = start >> PAGE_CACHE_SHIFT;
1200 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1201 unsigned long nr_pages = end_index - index + 1;
1204 if (index == locked_page->index && end_index == index)
1207 while (nr_pages > 0) {
1208 ret = find_get_pages_contig(inode->i_mapping, index,
1209 min_t(unsigned long, nr_pages,
1210 ARRAY_SIZE(pages)), pages);
1211 for (i = 0; i < ret; i++) {
1212 if (pages[i] != locked_page)
1213 unlock_page(pages[i]);
1214 page_cache_release(pages[i]);
1223 static noinline int lock_delalloc_pages(struct inode *inode,
1224 struct page *locked_page,
1228 unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
1229 unsigned long start_index = index;
1230 unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
1231 unsigned long pages_locked = 0;
1232 struct page *pages[16];
1233 unsigned long nrpages;
1237 /* the caller is responsible for locking the start index */
1238 if (index == locked_page->index && index == end_index)
1241 /* skip the page at the start index */
1242 nrpages = end_index - index + 1;
1243 while (nrpages > 0) {
1244 ret = find_get_pages_contig(inode->i_mapping, index,
1245 min_t(unsigned long,
1246 nrpages, ARRAY_SIZE(pages)), pages);
1251 /* now we have an array of pages, lock them all */
1252 for (i = 0; i < ret; i++) {
1254 * the caller is taking responsibility for
1257 if (pages[i] != locked_page) {
1258 lock_page(pages[i]);
1259 if (!PageDirty(pages[i]) ||
1260 pages[i]->mapping != inode->i_mapping) {
1262 unlock_page(pages[i]);
1263 page_cache_release(pages[i]);
1267 page_cache_release(pages[i]);
1276 if (ret && pages_locked) {
1277 __unlock_for_delalloc(inode, locked_page,
1279 ((u64)(start_index + pages_locked - 1)) <<
1286 * find a contiguous range of bytes in the file marked as delalloc, not
1287 * more than 'max_bytes'. start and end are used to return the range,
1289 * 1 is returned if we find something, 0 if nothing was in the tree
1291 static noinline u64 find_lock_delalloc_range(struct inode *inode,
1292 struct extent_io_tree *tree,
1293 struct page *locked_page,
1294 u64 *start, u64 *end,
1300 struct extent_state *cached_state = NULL;
1305 /* step one, find a bunch of delalloc bytes starting at start */
1306 delalloc_start = *start;
1308 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1309 max_bytes, &cached_state);
1310 if (!found || delalloc_end <= *start) {
1311 *start = delalloc_start;
1312 *end = delalloc_end;
1313 free_extent_state(cached_state);
1318 * start comes from the offset of locked_page. We have to lock
1319 * pages in order, so we can't process delalloc bytes before
1322 if (delalloc_start < *start)
1323 delalloc_start = *start;
1326 * make sure to limit the number of pages we try to lock down
1329 if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1330 delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
1332 /* step two, lock all the pages after the page that has start */
1333 ret = lock_delalloc_pages(inode, locked_page,
1334 delalloc_start, delalloc_end);
1335 if (ret == -EAGAIN) {
1336 /* some of the pages are gone, lets avoid looping by
1337 * shortening the size of the delalloc range we're searching
1339 free_extent_state(cached_state);
1341 unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
1342 max_bytes = PAGE_CACHE_SIZE - offset;
1352 /* step three, lock the state bits for the whole range */
1353 lock_extent_bits(tree, delalloc_start, delalloc_end,
1354 0, &cached_state, GFP_NOFS);
1356 /* then test to make sure it is all still delalloc */
1357 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1358 EXTENT_DELALLOC, 1, cached_state);
1360 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1361 &cached_state, GFP_NOFS);
1362 __unlock_for_delalloc(inode, locked_page,
1363 delalloc_start, delalloc_end);
1367 free_extent_state(cached_state);
1368 *start = delalloc_start;
1369 *end = delalloc_end;
1374 int extent_clear_unlock_delalloc(struct inode *inode,
1375 struct extent_io_tree *tree,
1376 u64 start, u64 end, struct page *locked_page,
1380 struct page *pages[16];
1381 unsigned long index = start >> PAGE_CACHE_SHIFT;
1382 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1383 unsigned long nr_pages = end_index - index + 1;
1387 if (op & EXTENT_CLEAR_UNLOCK)
1388 clear_bits |= EXTENT_LOCKED;
1389 if (op & EXTENT_CLEAR_DIRTY)
1390 clear_bits |= EXTENT_DIRTY;
1392 if (op & EXTENT_CLEAR_DELALLOC)
1393 clear_bits |= EXTENT_DELALLOC;
1395 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1396 if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
1397 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
1398 EXTENT_SET_PRIVATE2)))
1401 while (nr_pages > 0) {
1402 ret = find_get_pages_contig(inode->i_mapping, index,
1403 min_t(unsigned long,
1404 nr_pages, ARRAY_SIZE(pages)), pages);
1405 for (i = 0; i < ret; i++) {
1407 if (op & EXTENT_SET_PRIVATE2)
1408 SetPagePrivate2(pages[i]);
1410 if (pages[i] == locked_page) {
1411 page_cache_release(pages[i]);
1414 if (op & EXTENT_CLEAR_DIRTY)
1415 clear_page_dirty_for_io(pages[i]);
1416 if (op & EXTENT_SET_WRITEBACK)
1417 set_page_writeback(pages[i]);
1418 if (op & EXTENT_END_WRITEBACK)
1419 end_page_writeback(pages[i]);
1420 if (op & EXTENT_CLEAR_UNLOCK_PAGE)
1421 unlock_page(pages[i]);
1422 page_cache_release(pages[i]);
1432 * count the number of bytes in the tree that have a given bit(s)
1433 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1434 * cached. The total number found is returned.
1436 u64 count_range_bits(struct extent_io_tree *tree,
1437 u64 *start, u64 search_end, u64 max_bytes,
1438 unsigned long bits, int contig)
1440 struct rb_node *node;
1441 struct extent_state *state;
1442 u64 cur_start = *start;
1443 u64 total_bytes = 0;
1447 if (search_end <= cur_start) {
1452 spin_lock(&tree->lock);
1453 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1454 total_bytes = tree->dirty_bytes;
1458 * this search will find all the extents that end after
1461 node = tree_search(tree, cur_start);
1466 state = rb_entry(node, struct extent_state, rb_node);
1467 if (state->start > search_end)
1469 if (contig && found && state->start > last + 1)
1471 if (state->end >= cur_start && (state->state & bits) == bits) {
1472 total_bytes += min(search_end, state->end) + 1 -
1473 max(cur_start, state->start);
1474 if (total_bytes >= max_bytes)
1477 *start = max(cur_start, state->start);
1481 } else if (contig && found) {
1484 node = rb_next(node);
1489 spin_unlock(&tree->lock);
1494 * set the private field for a given byte offset in the tree. If there isn't
1495 * an extent_state there already, this does nothing.
1497 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1499 struct rb_node *node;
1500 struct extent_state *state;
1503 spin_lock(&tree->lock);
1505 * this search will find all the extents that end after
1508 node = tree_search(tree, start);
1513 state = rb_entry(node, struct extent_state, rb_node);
1514 if (state->start != start) {
1518 state->private = private;
1520 spin_unlock(&tree->lock);
1524 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1526 struct rb_node *node;
1527 struct extent_state *state;
1530 spin_lock(&tree->lock);
1532 * this search will find all the extents that end after
1535 node = tree_search(tree, start);
1540 state = rb_entry(node, struct extent_state, rb_node);
1541 if (state->start != start) {
1545 *private = state->private;
1547 spin_unlock(&tree->lock);
1552 * searches a range in the state tree for a given mask.
1553 * If 'filled' == 1, this returns 1 only if every extent in the tree
1554 * has the bits set. Otherwise, 1 is returned if any bit in the
1555 * range is found set.
1557 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1558 int bits, int filled, struct extent_state *cached)
1560 struct extent_state *state = NULL;
1561 struct rb_node *node;
1564 spin_lock(&tree->lock);
1565 if (cached && cached->tree && cached->start <= start &&
1566 cached->end > start)
1567 node = &cached->rb_node;
1569 node = tree_search(tree, start);
1570 while (node && start <= end) {
1571 state = rb_entry(node, struct extent_state, rb_node);
1573 if (filled && state->start > start) {
1578 if (state->start > end)
1581 if (state->state & bits) {
1585 } else if (filled) {
1590 if (state->end == (u64)-1)
1593 start = state->end + 1;
1596 node = rb_next(node);
1603 spin_unlock(&tree->lock);
1608 * helper function to set a given page up to date if all the
1609 * extents in the tree for that page are up to date
1611 static int check_page_uptodate(struct extent_io_tree *tree,
1614 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1615 u64 end = start + PAGE_CACHE_SIZE - 1;
1616 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1617 SetPageUptodate(page);
1622 * helper function to unlock a page if all the extents in the tree
1623 * for that page are unlocked
1625 static int check_page_locked(struct extent_io_tree *tree,
1628 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1629 u64 end = start + PAGE_CACHE_SIZE - 1;
1630 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
1636 * helper function to end page writeback if all the extents
1637 * in the tree for that page are done with writeback
1639 static int check_page_writeback(struct extent_io_tree *tree,
1642 end_page_writeback(page);
1646 /* lots and lots of room for performance fixes in the end_bio funcs */
1649 * after a writepage IO is done, we need to:
1650 * clear the uptodate bits on error
1651 * clear the writeback bits in the extent tree for this IO
1652 * end_page_writeback if the page has no more pending IO
1654 * Scheduling is not allowed, so the extent state tree is expected
1655 * to have one and only one object corresponding to this IO.
1657 static void end_bio_extent_writepage(struct bio *bio, int err)
1659 int uptodate = err == 0;
1660 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1661 struct extent_io_tree *tree;
1668 struct page *page = bvec->bv_page;
1669 tree = &BTRFS_I(page->mapping->host)->io_tree;
1671 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1673 end = start + bvec->bv_len - 1;
1675 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1680 if (--bvec >= bio->bi_io_vec)
1681 prefetchw(&bvec->bv_page->flags);
1682 if (tree->ops && tree->ops->writepage_end_io_hook) {
1683 ret = tree->ops->writepage_end_io_hook(page, start,
1684 end, NULL, uptodate);
1689 if (!uptodate && tree->ops &&
1690 tree->ops->writepage_io_failed_hook) {
1691 ret = tree->ops->writepage_io_failed_hook(bio, page,
1694 uptodate = (err == 0);
1700 clear_extent_uptodate(tree, start, end, NULL, GFP_NOFS);
1701 ClearPageUptodate(page);
1706 end_page_writeback(page);
1708 check_page_writeback(tree, page);
1709 } while (bvec >= bio->bi_io_vec);
1715 * after a readpage IO is done, we need to:
1716 * clear the uptodate bits on error
1717 * set the uptodate bits if things worked
1718 * set the page up to date if all extents in the tree are uptodate
1719 * clear the lock bit in the extent tree
1720 * unlock the page if there are no other extents locked for it
1722 * Scheduling is not allowed, so the extent state tree is expected
1723 * to have one and only one object corresponding to this IO.
1725 static void end_bio_extent_readpage(struct bio *bio, int err)
1727 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1728 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
1729 struct bio_vec *bvec = bio->bi_io_vec;
1730 struct extent_io_tree *tree;
1740 struct page *page = bvec->bv_page;
1741 struct extent_state *cached = NULL;
1742 struct extent_state *state;
1744 tree = &BTRFS_I(page->mapping->host)->io_tree;
1746 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1748 end = start + bvec->bv_len - 1;
1750 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1755 if (++bvec <= bvec_end)
1756 prefetchw(&bvec->bv_page->flags);
1758 spin_lock(&tree->lock);
1759 state = find_first_extent_bit_state(tree, start, EXTENT_LOCKED);
1760 if (state && state->start == start) {
1762 * take a reference on the state, unlock will drop
1765 cache_state(state, &cached);
1767 spin_unlock(&tree->lock);
1769 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
1770 ret = tree->ops->readpage_end_io_hook(page, start, end,
1775 if (!uptodate && tree->ops &&
1776 tree->ops->readpage_io_failed_hook) {
1777 ret = tree->ops->readpage_io_failed_hook(bio, page,
1781 test_bit(BIO_UPTODATE, &bio->bi_flags);
1784 uncache_state(&cached);
1790 set_extent_uptodate(tree, start, end, &cached,
1793 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
1797 SetPageUptodate(page);
1799 ClearPageUptodate(page);
1805 check_page_uptodate(tree, page);
1807 ClearPageUptodate(page);
1810 check_page_locked(tree, page);
1812 } while (bvec <= bvec_end);
1818 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
1823 bio = bio_alloc(gfp_flags, nr_vecs);
1825 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
1826 while (!bio && (nr_vecs /= 2))
1827 bio = bio_alloc(gfp_flags, nr_vecs);
1832 bio->bi_bdev = bdev;
1833 bio->bi_sector = first_sector;
1838 static int submit_one_bio(int rw, struct bio *bio, int mirror_num,
1839 unsigned long bio_flags)
1842 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1843 struct page *page = bvec->bv_page;
1844 struct extent_io_tree *tree = bio->bi_private;
1847 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1849 bio->bi_private = NULL;
1853 if (tree->ops && tree->ops->submit_bio_hook)
1854 ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
1855 mirror_num, bio_flags, start);
1857 submit_bio(rw, bio);
1858 if (bio_flagged(bio, BIO_EOPNOTSUPP))
1864 static int submit_extent_page(int rw, struct extent_io_tree *tree,
1865 struct page *page, sector_t sector,
1866 size_t size, unsigned long offset,
1867 struct block_device *bdev,
1868 struct bio **bio_ret,
1869 unsigned long max_pages,
1870 bio_end_io_t end_io_func,
1872 unsigned long prev_bio_flags,
1873 unsigned long bio_flags)
1879 int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
1880 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
1881 size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
1883 if (bio_ret && *bio_ret) {
1886 contig = bio->bi_sector == sector;
1888 contig = bio->bi_sector + (bio->bi_size >> 9) ==
1891 if (prev_bio_flags != bio_flags || !contig ||
1892 (tree->ops && tree->ops->merge_bio_hook &&
1893 tree->ops->merge_bio_hook(page, offset, page_size, bio,
1895 bio_add_page(bio, page, page_size, offset) < page_size) {
1896 ret = submit_one_bio(rw, bio, mirror_num,
1903 if (this_compressed)
1906 nr = bio_get_nr_vecs(bdev);
1908 bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
1912 bio_add_page(bio, page, page_size, offset);
1913 bio->bi_end_io = end_io_func;
1914 bio->bi_private = tree;
1919 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
1924 void set_page_extent_mapped(struct page *page)
1926 if (!PagePrivate(page)) {
1927 SetPagePrivate(page);
1928 page_cache_get(page);
1929 set_page_private(page, EXTENT_PAGE_PRIVATE);
1933 static void set_page_extent_head(struct page *page, unsigned long len)
1935 WARN_ON(!PagePrivate(page));
1936 set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
1940 * basic readpage implementation. Locked extent state structs are inserted
1941 * into the tree that are removed when the IO is done (by the end_io
1944 static int __extent_read_full_page(struct extent_io_tree *tree,
1946 get_extent_t *get_extent,
1947 struct bio **bio, int mirror_num,
1948 unsigned long *bio_flags)
1950 struct inode *inode = page->mapping->host;
1951 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1952 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1956 u64 last_byte = i_size_read(inode);
1960 struct extent_map *em;
1961 struct block_device *bdev;
1962 struct btrfs_ordered_extent *ordered;
1965 size_t pg_offset = 0;
1967 size_t disk_io_size;
1968 size_t blocksize = inode->i_sb->s_blocksize;
1969 unsigned long this_bio_flag = 0;
1971 set_page_extent_mapped(page);
1973 if (!PageUptodate(page)) {
1974 if (cleancache_get_page(page) == 0) {
1975 BUG_ON(blocksize != PAGE_SIZE);
1982 lock_extent(tree, start, end, GFP_NOFS);
1983 ordered = btrfs_lookup_ordered_extent(inode, start);
1986 unlock_extent(tree, start, end, GFP_NOFS);
1987 btrfs_start_ordered_extent(inode, ordered, 1);
1988 btrfs_put_ordered_extent(ordered);
1991 if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
1993 size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
1996 iosize = PAGE_CACHE_SIZE - zero_offset;
1997 userpage = kmap_atomic(page, KM_USER0);
1998 memset(userpage + zero_offset, 0, iosize);
1999 flush_dcache_page(page);
2000 kunmap_atomic(userpage, KM_USER0);
2003 while (cur <= end) {
2004 if (cur >= last_byte) {
2006 struct extent_state *cached = NULL;
2008 iosize = PAGE_CACHE_SIZE - pg_offset;
2009 userpage = kmap_atomic(page, KM_USER0);
2010 memset(userpage + pg_offset, 0, iosize);
2011 flush_dcache_page(page);
2012 kunmap_atomic(userpage, KM_USER0);
2013 set_extent_uptodate(tree, cur, cur + iosize - 1,
2015 unlock_extent_cached(tree, cur, cur + iosize - 1,
2019 em = get_extent(inode, page, pg_offset, cur,
2021 if (IS_ERR_OR_NULL(em)) {
2023 unlock_extent(tree, cur, end, GFP_NOFS);
2026 extent_offset = cur - em->start;
2027 BUG_ON(extent_map_end(em) <= cur);
2030 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2031 this_bio_flag = EXTENT_BIO_COMPRESSED;
2032 extent_set_compress_type(&this_bio_flag,
2036 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2037 cur_end = min(extent_map_end(em) - 1, end);
2038 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2039 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2040 disk_io_size = em->block_len;
2041 sector = em->block_start >> 9;
2043 sector = (em->block_start + extent_offset) >> 9;
2044 disk_io_size = iosize;
2047 block_start = em->block_start;
2048 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2049 block_start = EXTENT_MAP_HOLE;
2050 free_extent_map(em);
2053 /* we've found a hole, just zero and go on */
2054 if (block_start == EXTENT_MAP_HOLE) {
2056 struct extent_state *cached = NULL;
2058 userpage = kmap_atomic(page, KM_USER0);
2059 memset(userpage + pg_offset, 0, iosize);
2060 flush_dcache_page(page);
2061 kunmap_atomic(userpage, KM_USER0);
2063 set_extent_uptodate(tree, cur, cur + iosize - 1,
2065 unlock_extent_cached(tree, cur, cur + iosize - 1,
2068 pg_offset += iosize;
2071 /* the get_extent function already copied into the page */
2072 if (test_range_bit(tree, cur, cur_end,
2073 EXTENT_UPTODATE, 1, NULL)) {
2074 check_page_uptodate(tree, page);
2075 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2077 pg_offset += iosize;
2080 /* we have an inline extent but it didn't get marked up
2081 * to date. Error out
2083 if (block_start == EXTENT_MAP_INLINE) {
2085 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2087 pg_offset += iosize;
2092 if (tree->ops && tree->ops->readpage_io_hook) {
2093 ret = tree->ops->readpage_io_hook(page, cur,
2097 unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
2099 ret = submit_extent_page(READ, tree, page,
2100 sector, disk_io_size, pg_offset,
2102 end_bio_extent_readpage, mirror_num,
2106 *bio_flags = this_bio_flag;
2111 pg_offset += iosize;
2115 if (!PageError(page))
2116 SetPageUptodate(page);
2122 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
2123 get_extent_t *get_extent)
2125 struct bio *bio = NULL;
2126 unsigned long bio_flags = 0;
2129 ret = __extent_read_full_page(tree, page, get_extent, &bio, 0,
2132 ret = submit_one_bio(READ, bio, 0, bio_flags);
2136 static noinline void update_nr_written(struct page *page,
2137 struct writeback_control *wbc,
2138 unsigned long nr_written)
2140 wbc->nr_to_write -= nr_written;
2141 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
2142 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
2143 page->mapping->writeback_index = page->index + nr_written;
2147 * the writepage semantics are similar to regular writepage. extent
2148 * records are inserted to lock ranges in the tree, and as dirty areas
2149 * are found, they are marked writeback. Then the lock bits are removed
2150 * and the end_io handler clears the writeback ranges
2152 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
2155 struct inode *inode = page->mapping->host;
2156 struct extent_page_data *epd = data;
2157 struct extent_io_tree *tree = epd->tree;
2158 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2160 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2164 u64 last_byte = i_size_read(inode);
2168 struct extent_state *cached_state = NULL;
2169 struct extent_map *em;
2170 struct block_device *bdev;
2173 size_t pg_offset = 0;
2175 loff_t i_size = i_size_read(inode);
2176 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
2182 unsigned long nr_written = 0;
2184 if (wbc->sync_mode == WB_SYNC_ALL)
2185 write_flags = WRITE_SYNC;
2187 write_flags = WRITE;
2189 trace___extent_writepage(page, inode, wbc);
2191 WARN_ON(!PageLocked(page));
2192 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2193 if (page->index > end_index ||
2194 (page->index == end_index && !pg_offset)) {
2195 page->mapping->a_ops->invalidatepage(page, 0);
2200 if (page->index == end_index) {
2203 userpage = kmap_atomic(page, KM_USER0);
2204 memset(userpage + pg_offset, 0,
2205 PAGE_CACHE_SIZE - pg_offset);
2206 kunmap_atomic(userpage, KM_USER0);
2207 flush_dcache_page(page);
2211 set_page_extent_mapped(page);
2213 delalloc_start = start;
2216 if (!epd->extent_locked) {
2217 u64 delalloc_to_write = 0;
2219 * make sure the wbc mapping index is at least updated
2222 update_nr_written(page, wbc, 0);
2224 while (delalloc_end < page_end) {
2225 nr_delalloc = find_lock_delalloc_range(inode, tree,
2230 if (nr_delalloc == 0) {
2231 delalloc_start = delalloc_end + 1;
2234 tree->ops->fill_delalloc(inode, page, delalloc_start,
2235 delalloc_end, &page_started,
2238 * delalloc_end is already one less than the total
2239 * length, so we don't subtract one from
2242 delalloc_to_write += (delalloc_end - delalloc_start +
2245 delalloc_start = delalloc_end + 1;
2247 if (wbc->nr_to_write < delalloc_to_write) {
2250 if (delalloc_to_write < thresh * 2)
2251 thresh = delalloc_to_write;
2252 wbc->nr_to_write = min_t(u64, delalloc_to_write,
2256 /* did the fill delalloc function already unlock and start
2262 * we've unlocked the page, so we can't update
2263 * the mapping's writeback index, just update
2266 wbc->nr_to_write -= nr_written;
2270 if (tree->ops && tree->ops->writepage_start_hook) {
2271 ret = tree->ops->writepage_start_hook(page, start,
2273 if (ret == -EAGAIN) {
2274 redirty_page_for_writepage(wbc, page);
2275 update_nr_written(page, wbc, nr_written);
2283 * we don't want to touch the inode after unlocking the page,
2284 * so we update the mapping writeback index now
2286 update_nr_written(page, wbc, nr_written + 1);
2289 if (last_byte <= start) {
2290 if (tree->ops && tree->ops->writepage_end_io_hook)
2291 tree->ops->writepage_end_io_hook(page, start,
2296 blocksize = inode->i_sb->s_blocksize;
2298 while (cur <= end) {
2299 if (cur >= last_byte) {
2300 if (tree->ops && tree->ops->writepage_end_io_hook)
2301 tree->ops->writepage_end_io_hook(page, cur,
2305 em = epd->get_extent(inode, page, pg_offset, cur,
2307 if (IS_ERR_OR_NULL(em)) {
2312 extent_offset = cur - em->start;
2313 BUG_ON(extent_map_end(em) <= cur);
2315 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2316 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2317 sector = (em->block_start + extent_offset) >> 9;
2319 block_start = em->block_start;
2320 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
2321 free_extent_map(em);
2325 * compressed and inline extents are written through other
2328 if (compressed || block_start == EXTENT_MAP_HOLE ||
2329 block_start == EXTENT_MAP_INLINE) {
2331 * end_io notification does not happen here for
2332 * compressed extents
2334 if (!compressed && tree->ops &&
2335 tree->ops->writepage_end_io_hook)
2336 tree->ops->writepage_end_io_hook(page, cur,
2339 else if (compressed) {
2340 /* we don't want to end_page_writeback on
2341 * a compressed extent. this happens
2348 pg_offset += iosize;
2351 /* leave this out until we have a page_mkwrite call */
2352 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
2353 EXTENT_DIRTY, 0, NULL)) {
2355 pg_offset += iosize;
2359 if (tree->ops && tree->ops->writepage_io_hook) {
2360 ret = tree->ops->writepage_io_hook(page, cur,
2368 unsigned long max_nr = end_index + 1;
2370 set_range_writeback(tree, cur, cur + iosize - 1);
2371 if (!PageWriteback(page)) {
2372 printk(KERN_ERR "btrfs warning page %lu not "
2373 "writeback, cur %llu end %llu\n",
2374 page->index, (unsigned long long)cur,
2375 (unsigned long long)end);
2378 ret = submit_extent_page(write_flags, tree, page,
2379 sector, iosize, pg_offset,
2380 bdev, &epd->bio, max_nr,
2381 end_bio_extent_writepage,
2387 pg_offset += iosize;
2392 /* make sure the mapping tag for page dirty gets cleared */
2393 set_page_writeback(page);
2394 end_page_writeback(page);
2400 /* drop our reference on any cached states */
2401 free_extent_state(cached_state);
2406 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2407 * @mapping: address space structure to write
2408 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2409 * @writepage: function called for each page
2410 * @data: data passed to writepage function
2412 * If a page is already under I/O, write_cache_pages() skips it, even
2413 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2414 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2415 * and msync() need to guarantee that all the data which was dirty at the time
2416 * the call was made get new I/O started against them. If wbc->sync_mode is
2417 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2418 * existing IO to complete.
2420 static int extent_write_cache_pages(struct extent_io_tree *tree,
2421 struct address_space *mapping,
2422 struct writeback_control *wbc,
2423 writepage_t writepage, void *data,
2424 void (*flush_fn)(void *))
2428 int nr_to_write_done = 0;
2429 struct pagevec pvec;
2432 pgoff_t end; /* Inclusive */
2436 pagevec_init(&pvec, 0);
2437 if (wbc->range_cyclic) {
2438 index = mapping->writeback_index; /* Start from prev offset */
2441 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2442 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2445 if (wbc->sync_mode == WB_SYNC_ALL)
2446 tag = PAGECACHE_TAG_TOWRITE;
2448 tag = PAGECACHE_TAG_DIRTY;
2450 if (wbc->sync_mode == WB_SYNC_ALL)
2451 tag_pages_for_writeback(mapping, index, end);
2452 while (!done && !nr_to_write_done && (index <= end) &&
2453 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
2454 min(end - index, (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,
2560 .range_start = page_offset(page) + PAGE_CACHE_SIZE,
2561 .range_end = (loff_t)-1,
2564 ret = __extent_writepage(page, wbc, &epd);
2566 extent_write_cache_pages(tree, mapping, &wbc_writepages,
2567 __extent_writepage, &epd, flush_write_bio);
2568 flush_epd_write_bio(&epd);
2572 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
2573 u64 start, u64 end, get_extent_t *get_extent,
2577 struct address_space *mapping = inode->i_mapping;
2579 unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
2582 struct extent_page_data epd = {
2585 .get_extent = get_extent,
2587 .sync_io = mode == WB_SYNC_ALL,
2589 struct writeback_control wbc_writepages = {
2591 .nr_to_write = nr_pages * 2,
2592 .range_start = start,
2593 .range_end = end + 1,
2596 while (start <= end) {
2597 page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
2598 if (clear_page_dirty_for_io(page))
2599 ret = __extent_writepage(page, &wbc_writepages, &epd);
2601 if (tree->ops && tree->ops->writepage_end_io_hook)
2602 tree->ops->writepage_end_io_hook(page, start,
2603 start + PAGE_CACHE_SIZE - 1,
2607 page_cache_release(page);
2608 start += PAGE_CACHE_SIZE;
2611 flush_epd_write_bio(&epd);
2615 int extent_writepages(struct extent_io_tree *tree,
2616 struct address_space *mapping,
2617 get_extent_t *get_extent,
2618 struct writeback_control *wbc)
2621 struct extent_page_data epd = {
2624 .get_extent = get_extent,
2626 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
2629 ret = extent_write_cache_pages(tree, mapping, wbc,
2630 __extent_writepage, &epd,
2632 flush_epd_write_bio(&epd);
2636 int extent_readpages(struct extent_io_tree *tree,
2637 struct address_space *mapping,
2638 struct list_head *pages, unsigned nr_pages,
2639 get_extent_t get_extent)
2641 struct bio *bio = NULL;
2643 unsigned long bio_flags = 0;
2645 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
2646 struct page *page = list_entry(pages->prev, struct page, lru);
2648 prefetchw(&page->flags);
2649 list_del(&page->lru);
2650 if (!add_to_page_cache_lru(page, mapping,
2651 page->index, GFP_NOFS)) {
2652 __extent_read_full_page(tree, page, get_extent,
2653 &bio, 0, &bio_flags);
2655 page_cache_release(page);
2657 BUG_ON(!list_empty(pages));
2659 submit_one_bio(READ, bio, 0, bio_flags);
2664 * basic invalidatepage code, this waits on any locked or writeback
2665 * ranges corresponding to the page, and then deletes any extent state
2666 * records from the tree
2668 int extent_invalidatepage(struct extent_io_tree *tree,
2669 struct page *page, unsigned long offset)
2671 struct extent_state *cached_state = NULL;
2672 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
2673 u64 end = start + PAGE_CACHE_SIZE - 1;
2674 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
2676 start += (offset + blocksize - 1) & ~(blocksize - 1);
2680 lock_extent_bits(tree, start, end, 0, &cached_state, GFP_NOFS);
2681 wait_on_page_writeback(page);
2682 clear_extent_bit(tree, start, end,
2683 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
2684 EXTENT_DO_ACCOUNTING,
2685 1, 1, &cached_state, GFP_NOFS);
2690 * a helper for releasepage, this tests for areas of the page that
2691 * are locked or under IO and drops the related state bits if it is safe
2694 int try_release_extent_state(struct extent_map_tree *map,
2695 struct extent_io_tree *tree, struct page *page,
2698 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2699 u64 end = start + PAGE_CACHE_SIZE - 1;
2702 if (test_range_bit(tree, start, end,
2703 EXTENT_IOBITS, 0, NULL))
2706 if ((mask & GFP_NOFS) == GFP_NOFS)
2709 * at this point we can safely clear everything except the
2710 * locked bit and the nodatasum bit
2712 ret = clear_extent_bit(tree, start, end,
2713 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
2716 /* if clear_extent_bit failed for enomem reasons,
2717 * we can't allow the release to continue.
2728 * a helper for releasepage. As long as there are no locked extents
2729 * in the range corresponding to the page, both state records and extent
2730 * map records are removed
2732 int try_release_extent_mapping(struct extent_map_tree *map,
2733 struct extent_io_tree *tree, struct page *page,
2736 struct extent_map *em;
2737 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2738 u64 end = start + PAGE_CACHE_SIZE - 1;
2740 if ((mask & __GFP_WAIT) &&
2741 page->mapping->host->i_size > 16 * 1024 * 1024) {
2743 while (start <= end) {
2744 len = end - start + 1;
2745 write_lock(&map->lock);
2746 em = lookup_extent_mapping(map, start, len);
2747 if (IS_ERR_OR_NULL(em)) {
2748 write_unlock(&map->lock);
2751 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
2752 em->start != start) {
2753 write_unlock(&map->lock);
2754 free_extent_map(em);
2757 if (!test_range_bit(tree, em->start,
2758 extent_map_end(em) - 1,
2759 EXTENT_LOCKED | EXTENT_WRITEBACK,
2761 remove_extent_mapping(map, em);
2762 /* once for the rb tree */
2763 free_extent_map(em);
2765 start = extent_map_end(em);
2766 write_unlock(&map->lock);
2769 free_extent_map(em);
2772 return try_release_extent_state(map, tree, page, mask);
2776 * helper function for fiemap, which doesn't want to see any holes.
2777 * This maps until we find something past 'last'
2779 static struct extent_map *get_extent_skip_holes(struct inode *inode,
2782 get_extent_t *get_extent)
2784 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
2785 struct extent_map *em;
2792 len = last - offset;
2795 len = (len + sectorsize - 1) & ~(sectorsize - 1);
2796 em = get_extent(inode, NULL, 0, offset, len, 0);
2797 if (IS_ERR_OR_NULL(em))
2800 /* if this isn't a hole return it */
2801 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
2802 em->block_start != EXTENT_MAP_HOLE) {
2806 /* this is a hole, advance to the next extent */
2807 offset = extent_map_end(em);
2808 free_extent_map(em);
2815 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2816 __u64 start, __u64 len, get_extent_t *get_extent)
2820 u64 max = start + len;
2824 u64 last_for_get_extent = 0;
2826 u64 isize = i_size_read(inode);
2827 struct btrfs_key found_key;
2828 struct extent_map *em = NULL;
2829 struct extent_state *cached_state = NULL;
2830 struct btrfs_path *path;
2831 struct btrfs_file_extent_item *item;
2836 unsigned long emflags;
2841 path = btrfs_alloc_path();
2844 path->leave_spinning = 1;
2847 * lookup the last file extent. We're not using i_size here
2848 * because there might be preallocation past i_size
2850 ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
2851 path, btrfs_ino(inode), -1, 0);
2853 btrfs_free_path(path);
2858 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2859 struct btrfs_file_extent_item);
2860 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
2861 found_type = btrfs_key_type(&found_key);
2863 /* No extents, but there might be delalloc bits */
2864 if (found_key.objectid != btrfs_ino(inode) ||
2865 found_type != BTRFS_EXTENT_DATA_KEY) {
2866 /* have to trust i_size as the end */
2868 last_for_get_extent = isize;
2871 * remember the start of the last extent. There are a
2872 * bunch of different factors that go into the length of the
2873 * extent, so its much less complex to remember where it started
2875 last = found_key.offset;
2876 last_for_get_extent = last + 1;
2878 btrfs_free_path(path);
2881 * we might have some extents allocated but more delalloc past those
2882 * extents. so, we trust isize unless the start of the last extent is
2887 last_for_get_extent = isize;
2890 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
2891 &cached_state, GFP_NOFS);
2893 em = get_extent_skip_holes(inode, off, last_for_get_extent,
2903 u64 offset_in_extent;
2905 /* break if the extent we found is outside the range */
2906 if (em->start >= max || extent_map_end(em) < off)
2910 * get_extent may return an extent that starts before our
2911 * requested range. We have to make sure the ranges
2912 * we return to fiemap always move forward and don't
2913 * overlap, so adjust the offsets here
2915 em_start = max(em->start, off);
2918 * record the offset from the start of the extent
2919 * for adjusting the disk offset below
2921 offset_in_extent = em_start - em->start;
2922 em_end = extent_map_end(em);
2923 em_len = em_end - em_start;
2924 emflags = em->flags;
2929 * bump off for our next call to get_extent
2931 off = extent_map_end(em);
2935 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
2937 flags |= FIEMAP_EXTENT_LAST;
2938 } else if (em->block_start == EXTENT_MAP_INLINE) {
2939 flags |= (FIEMAP_EXTENT_DATA_INLINE |
2940 FIEMAP_EXTENT_NOT_ALIGNED);
2941 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
2942 flags |= (FIEMAP_EXTENT_DELALLOC |
2943 FIEMAP_EXTENT_UNKNOWN);
2945 disko = em->block_start + offset_in_extent;
2947 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
2948 flags |= FIEMAP_EXTENT_ENCODED;
2950 free_extent_map(em);
2952 if ((em_start >= last) || em_len == (u64)-1 ||
2953 (last == (u64)-1 && isize <= em_end)) {
2954 flags |= FIEMAP_EXTENT_LAST;
2958 /* now scan forward to see if this is really the last extent. */
2959 em = get_extent_skip_holes(inode, off, last_for_get_extent,
2966 flags |= FIEMAP_EXTENT_LAST;
2969 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
2975 free_extent_map(em);
2977 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len,
2978 &cached_state, GFP_NOFS);
2982 static inline struct page *extent_buffer_page(struct extent_buffer *eb,
2986 struct address_space *mapping;
2989 return eb->first_page;
2990 i += eb->start >> PAGE_CACHE_SHIFT;
2991 mapping = eb->first_page->mapping;
2996 * extent_buffer_page is only called after pinning the page
2997 * by increasing the reference count. So we know the page must
2998 * be in the radix tree.
3001 p = radix_tree_lookup(&mapping->page_tree, i);
3007 static inline unsigned long num_extent_pages(u64 start, u64 len)
3009 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
3010 (start >> PAGE_CACHE_SHIFT);
3013 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
3018 struct extent_buffer *eb = NULL;
3020 unsigned long flags;
3023 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
3028 rwlock_init(&eb->lock);
3029 atomic_set(&eb->write_locks, 0);
3030 atomic_set(&eb->read_locks, 0);
3031 atomic_set(&eb->blocking_readers, 0);
3032 atomic_set(&eb->blocking_writers, 0);
3033 atomic_set(&eb->spinning_readers, 0);
3034 atomic_set(&eb->spinning_writers, 0);
3035 init_waitqueue_head(&eb->write_lock_wq);
3036 init_waitqueue_head(&eb->read_lock_wq);
3039 spin_lock_irqsave(&leak_lock, flags);
3040 list_add(&eb->leak_list, &buffers);
3041 spin_unlock_irqrestore(&leak_lock, flags);
3043 atomic_set(&eb->refs, 1);
3048 static void __free_extent_buffer(struct extent_buffer *eb)
3051 unsigned long flags;
3052 spin_lock_irqsave(&leak_lock, flags);
3053 list_del(&eb->leak_list);
3054 spin_unlock_irqrestore(&leak_lock, flags);
3056 kmem_cache_free(extent_buffer_cache, eb);
3060 * Helper for releasing extent buffer page.
3062 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
3063 unsigned long start_idx)
3065 unsigned long index;
3068 if (!eb->first_page)
3071 index = num_extent_pages(eb->start, eb->len);
3072 if (start_idx >= index)
3077 page = extent_buffer_page(eb, index);
3079 page_cache_release(page);
3080 } while (index != start_idx);
3084 * Helper for releasing the extent buffer.
3086 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
3088 btrfs_release_extent_buffer_page(eb, 0);
3089 __free_extent_buffer(eb);
3092 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
3093 u64 start, unsigned long len,
3096 unsigned long num_pages = num_extent_pages(start, len);
3098 unsigned long index = start >> PAGE_CACHE_SHIFT;
3099 struct extent_buffer *eb;
3100 struct extent_buffer *exists = NULL;
3102 struct address_space *mapping = tree->mapping;
3107 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3108 if (eb && atomic_inc_not_zero(&eb->refs)) {
3110 mark_page_accessed(eb->first_page);
3115 eb = __alloc_extent_buffer(tree, start, len, GFP_NOFS);
3120 eb->first_page = page0;
3123 page_cache_get(page0);
3124 mark_page_accessed(page0);
3125 set_page_extent_mapped(page0);
3126 set_page_extent_head(page0, len);
3127 uptodate = PageUptodate(page0);
3131 for (; i < num_pages; i++, index++) {
3132 p = find_or_create_page(mapping, index, GFP_NOFS);
3137 set_page_extent_mapped(p);
3138 mark_page_accessed(p);
3141 set_page_extent_head(p, len);
3143 set_page_private(p, EXTENT_PAGE_PRIVATE);
3145 if (!PageUptodate(p))
3149 * see below about how we avoid a nasty race with release page
3150 * and why we unlock later
3156 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3158 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
3162 spin_lock(&tree->buffer_lock);
3163 ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
3164 if (ret == -EEXIST) {
3165 exists = radix_tree_lookup(&tree->buffer,
3166 start >> PAGE_CACHE_SHIFT);
3167 /* add one reference for the caller */
3168 atomic_inc(&exists->refs);
3169 spin_unlock(&tree->buffer_lock);
3170 radix_tree_preload_end();
3173 /* add one reference for the tree */
3174 atomic_inc(&eb->refs);
3175 spin_unlock(&tree->buffer_lock);
3176 radix_tree_preload_end();
3179 * there is a race where release page may have
3180 * tried to find this extent buffer in the radix
3181 * but failed. It will tell the VM it is safe to
3182 * reclaim the, and it will clear the page private bit.
3183 * We must make sure to set the page private bit properly
3184 * after the extent buffer is in the radix tree so
3185 * it doesn't get lost
3187 set_page_extent_mapped(eb->first_page);
3188 set_page_extent_head(eb->first_page, eb->len);
3190 unlock_page(eb->first_page);
3194 if (eb->first_page && !page0)
3195 unlock_page(eb->first_page);
3197 if (!atomic_dec_and_test(&eb->refs))
3199 btrfs_release_extent_buffer(eb);
3203 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
3204 u64 start, unsigned long len)
3206 struct extent_buffer *eb;
3209 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3210 if (eb && atomic_inc_not_zero(&eb->refs)) {
3212 mark_page_accessed(eb->first_page);
3220 void free_extent_buffer(struct extent_buffer *eb)
3225 if (!atomic_dec_and_test(&eb->refs))
3231 int clear_extent_buffer_dirty(struct extent_io_tree *tree,
3232 struct extent_buffer *eb)
3235 unsigned long num_pages;
3238 num_pages = num_extent_pages(eb->start, eb->len);
3240 for (i = 0; i < num_pages; i++) {
3241 page = extent_buffer_page(eb, i);
3242 if (!PageDirty(page))
3246 WARN_ON(!PagePrivate(page));
3248 set_page_extent_mapped(page);
3250 set_page_extent_head(page, eb->len);
3252 clear_page_dirty_for_io(page);
3253 spin_lock_irq(&page->mapping->tree_lock);
3254 if (!PageDirty(page)) {
3255 radix_tree_tag_clear(&page->mapping->page_tree,
3257 PAGECACHE_TAG_DIRTY);
3259 spin_unlock_irq(&page->mapping->tree_lock);
3265 int set_extent_buffer_dirty(struct extent_io_tree *tree,
3266 struct extent_buffer *eb)
3269 unsigned long num_pages;
3272 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
3273 num_pages = num_extent_pages(eb->start, eb->len);
3274 for (i = 0; i < num_pages; i++)
3275 __set_page_dirty_nobuffers(extent_buffer_page(eb, i));
3279 static int __eb_straddles_pages(u64 start, u64 len)
3281 if (len < PAGE_CACHE_SIZE)
3283 if (start & (PAGE_CACHE_SIZE - 1))
3285 if ((start + len) & (PAGE_CACHE_SIZE - 1))
3290 static int eb_straddles_pages(struct extent_buffer *eb)
3292 return __eb_straddles_pages(eb->start, eb->len);
3295 int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
3296 struct extent_buffer *eb,
3297 struct extent_state **cached_state)
3301 unsigned long num_pages;
3303 num_pages = num_extent_pages(eb->start, eb->len);
3304 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3306 if (eb_straddles_pages(eb)) {
3307 clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3308 cached_state, GFP_NOFS);
3310 for (i = 0; i < num_pages; i++) {
3311 page = extent_buffer_page(eb, i);
3313 ClearPageUptodate(page);
3318 int set_extent_buffer_uptodate(struct extent_io_tree *tree,
3319 struct extent_buffer *eb)
3323 unsigned long num_pages;
3325 num_pages = num_extent_pages(eb->start, eb->len);
3327 if (eb_straddles_pages(eb)) {
3328 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3331 for (i = 0; i < num_pages; i++) {
3332 page = extent_buffer_page(eb, i);
3333 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
3334 ((i == num_pages - 1) &&
3335 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
3336 check_page_uptodate(tree, page);
3339 SetPageUptodate(page);
3344 int extent_range_uptodate(struct extent_io_tree *tree,
3349 int pg_uptodate = 1;
3351 unsigned long index;
3353 if (__eb_straddles_pages(start, end - start + 1)) {
3354 ret = test_range_bit(tree, start, end,
3355 EXTENT_UPTODATE, 1, NULL);
3359 while (start <= end) {
3360 index = start >> PAGE_CACHE_SHIFT;
3361 page = find_get_page(tree->mapping, index);
3362 uptodate = PageUptodate(page);
3363 page_cache_release(page);
3368 start += PAGE_CACHE_SIZE;
3373 int extent_buffer_uptodate(struct extent_io_tree *tree,
3374 struct extent_buffer *eb,
3375 struct extent_state *cached_state)
3378 unsigned long num_pages;
3381 int pg_uptodate = 1;
3383 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3386 if (eb_straddles_pages(eb)) {
3387 ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3388 EXTENT_UPTODATE, 1, cached_state);
3393 num_pages = num_extent_pages(eb->start, eb->len);
3394 for (i = 0; i < num_pages; i++) {
3395 page = extent_buffer_page(eb, i);
3396 if (!PageUptodate(page)) {
3404 int read_extent_buffer_pages(struct extent_io_tree *tree,
3405 struct extent_buffer *eb,
3406 u64 start, int wait,
3407 get_extent_t *get_extent, int mirror_num)
3410 unsigned long start_i;
3414 int locked_pages = 0;
3415 int all_uptodate = 1;
3416 int inc_all_pages = 0;
3417 unsigned long num_pages;
3418 struct bio *bio = NULL;
3419 unsigned long bio_flags = 0;
3421 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3424 if (eb_straddles_pages(eb)) {
3425 if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3426 EXTENT_UPTODATE, 1, NULL)) {
3432 WARN_ON(start < eb->start);
3433 start_i = (start >> PAGE_CACHE_SHIFT) -
3434 (eb->start >> PAGE_CACHE_SHIFT);
3439 num_pages = num_extent_pages(eb->start, eb->len);
3440 for (i = start_i; i < num_pages; i++) {
3441 page = extent_buffer_page(eb, i);
3443 if (!trylock_page(page))
3449 if (!PageUptodate(page))
3454 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3458 for (i = start_i; i < num_pages; i++) {
3459 page = extent_buffer_page(eb, i);
3461 WARN_ON(!PagePrivate(page));
3463 set_page_extent_mapped(page);
3465 set_page_extent_head(page, eb->len);
3468 page_cache_get(page);
3469 if (!PageUptodate(page)) {
3472 ClearPageError(page);
3473 err = __extent_read_full_page(tree, page,
3475 mirror_num, &bio_flags);
3484 submit_one_bio(READ, bio, mirror_num, bio_flags);
3489 for (i = start_i; i < num_pages; i++) {
3490 page = extent_buffer_page(eb, i);
3491 wait_on_page_locked(page);
3492 if (!PageUptodate(page))
3497 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3502 while (locked_pages > 0) {
3503 page = extent_buffer_page(eb, i);
3511 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
3512 unsigned long start,
3519 char *dst = (char *)dstv;
3520 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3521 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3523 WARN_ON(start > eb->len);
3524 WARN_ON(start + len > eb->start + eb->len);
3526 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3529 page = extent_buffer_page(eb, i);
3531 cur = min(len, (PAGE_CACHE_SIZE - offset));
3532 kaddr = page_address(page);
3533 memcpy(dst, kaddr + offset, cur);
3542 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
3543 unsigned long min_len, char **map,
3544 unsigned long *map_start,
3545 unsigned long *map_len)
3547 size_t offset = start & (PAGE_CACHE_SIZE - 1);
3550 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3551 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3552 unsigned long end_i = (start_offset + start + min_len - 1) >>
3559 offset = start_offset;
3563 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
3566 if (start + min_len > eb->len) {
3567 printk(KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
3568 "wanted %lu %lu\n", (unsigned long long)eb->start,
3569 eb->len, start, min_len);
3574 p = extent_buffer_page(eb, i);
3575 kaddr = page_address(p);
3576 *map = kaddr + offset;
3577 *map_len = PAGE_CACHE_SIZE - offset;
3581 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
3582 unsigned long start,
3589 char *ptr = (char *)ptrv;
3590 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3591 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3594 WARN_ON(start > eb->len);
3595 WARN_ON(start + len > eb->start + eb->len);
3597 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3600 page = extent_buffer_page(eb, i);
3602 cur = min(len, (PAGE_CACHE_SIZE - offset));
3604 kaddr = page_address(page);
3605 ret = memcmp(ptr, kaddr + offset, cur);
3617 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
3618 unsigned long start, unsigned long len)
3624 char *src = (char *)srcv;
3625 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3626 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3628 WARN_ON(start > eb->len);
3629 WARN_ON(start + len > eb->start + eb->len);
3631 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3634 page = extent_buffer_page(eb, i);
3635 WARN_ON(!PageUptodate(page));
3637 cur = min(len, PAGE_CACHE_SIZE - offset);
3638 kaddr = page_address(page);
3639 memcpy(kaddr + offset, src, cur);
3648 void memset_extent_buffer(struct extent_buffer *eb, char c,
3649 unsigned long start, unsigned long len)
3655 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3656 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3658 WARN_ON(start > eb->len);
3659 WARN_ON(start + len > eb->start + eb->len);
3661 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3664 page = extent_buffer_page(eb, i);
3665 WARN_ON(!PageUptodate(page));
3667 cur = min(len, PAGE_CACHE_SIZE - offset);
3668 kaddr = page_address(page);
3669 memset(kaddr + offset, c, cur);
3677 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
3678 unsigned long dst_offset, unsigned long src_offset,
3681 u64 dst_len = dst->len;
3686 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3687 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3689 WARN_ON(src->len != dst_len);
3691 offset = (start_offset + dst_offset) &
3692 ((unsigned long)PAGE_CACHE_SIZE - 1);
3695 page = extent_buffer_page(dst, i);
3696 WARN_ON(!PageUptodate(page));
3698 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
3700 kaddr = page_address(page);
3701 read_extent_buffer(src, kaddr + offset, src_offset, cur);
3710 static void move_pages(struct page *dst_page, struct page *src_page,
3711 unsigned long dst_off, unsigned long src_off,
3714 char *dst_kaddr = page_address(dst_page);
3715 if (dst_page == src_page) {
3716 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
3718 char *src_kaddr = page_address(src_page);
3719 char *p = dst_kaddr + dst_off + len;
3720 char *s = src_kaddr + src_off + len;
3727 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
3729 unsigned long distance = (src > dst) ? src - dst : dst - src;
3730 return distance < len;
3733 static void copy_pages(struct page *dst_page, struct page *src_page,
3734 unsigned long dst_off, unsigned long src_off,
3737 char *dst_kaddr = page_address(dst_page);
3740 if (dst_page != src_page) {
3741 src_kaddr = page_address(src_page);
3743 src_kaddr = dst_kaddr;
3744 BUG_ON(areas_overlap(src_off, dst_off, len));
3747 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
3750 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3751 unsigned long src_offset, unsigned long len)
3754 size_t dst_off_in_page;
3755 size_t src_off_in_page;
3756 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3757 unsigned long dst_i;
3758 unsigned long src_i;
3760 if (src_offset + len > dst->len) {
3761 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
3762 "len %lu dst len %lu\n", src_offset, len, dst->len);
3765 if (dst_offset + len > dst->len) {
3766 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
3767 "len %lu dst len %lu\n", dst_offset, len, dst->len);
3772 dst_off_in_page = (start_offset + dst_offset) &
3773 ((unsigned long)PAGE_CACHE_SIZE - 1);
3774 src_off_in_page = (start_offset + src_offset) &
3775 ((unsigned long)PAGE_CACHE_SIZE - 1);
3777 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3778 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
3780 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
3782 cur = min_t(unsigned long, cur,
3783 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
3785 copy_pages(extent_buffer_page(dst, dst_i),
3786 extent_buffer_page(dst, src_i),
3787 dst_off_in_page, src_off_in_page, cur);
3795 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3796 unsigned long src_offset, unsigned long len)
3799 size_t dst_off_in_page;
3800 size_t src_off_in_page;
3801 unsigned long dst_end = dst_offset + len - 1;
3802 unsigned long src_end = src_offset + len - 1;
3803 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3804 unsigned long dst_i;
3805 unsigned long src_i;
3807 if (src_offset + len > dst->len) {
3808 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
3809 "len %lu len %lu\n", src_offset, len, dst->len);
3812 if (dst_offset + len > dst->len) {
3813 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
3814 "len %lu len %lu\n", dst_offset, len, dst->len);
3817 if (!areas_overlap(src_offset, dst_offset, len)) {
3818 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
3822 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
3823 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
3825 dst_off_in_page = (start_offset + dst_end) &
3826 ((unsigned long)PAGE_CACHE_SIZE - 1);
3827 src_off_in_page = (start_offset + src_end) &
3828 ((unsigned long)PAGE_CACHE_SIZE - 1);
3830 cur = min_t(unsigned long, len, src_off_in_page + 1);
3831 cur = min(cur, dst_off_in_page + 1);
3832 move_pages(extent_buffer_page(dst, dst_i),
3833 extent_buffer_page(dst, src_i),
3834 dst_off_in_page - cur + 1,
3835 src_off_in_page - cur + 1, cur);
3843 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
3845 struct extent_buffer *eb =
3846 container_of(head, struct extent_buffer, rcu_head);
3848 btrfs_release_extent_buffer(eb);
3851 int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
3853 u64 start = page_offset(page);
3854 struct extent_buffer *eb;
3857 spin_lock(&tree->buffer_lock);
3858 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3860 spin_unlock(&tree->buffer_lock);
3864 if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3870 * set @eb->refs to 0 if it is already 1, and then release the @eb.
3873 if (atomic_cmpxchg(&eb->refs, 1, 0) != 1) {
3878 radix_tree_delete(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3880 spin_unlock(&tree->buffer_lock);
3882 /* at this point we can safely release the extent buffer */
3883 if (atomic_read(&eb->refs) == 0)
3884 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);