1 #include <linux/bitops.h>
2 #include <linux/slab.h>
6 #include <linux/pagemap.h>
7 #include <linux/page-flags.h>
8 #include <linux/module.h>
9 #include <linux/spinlock.h>
10 #include <linux/blkdev.h>
11 #include <linux/swap.h>
12 #include <linux/writeback.h>
13 #include <linux/pagevec.h>
14 #include "extent_io.h"
15 #include "extent_map.h"
18 #include "btrfs_inode.h"
20 static struct kmem_cache *extent_state_cache;
21 static struct kmem_cache *extent_buffer_cache;
23 static LIST_HEAD(buffers);
24 static LIST_HEAD(states);
28 static DEFINE_SPINLOCK(leak_lock);
31 #define BUFFER_LRU_MAX 64
36 struct rb_node rb_node;
39 struct extent_page_data {
41 struct extent_io_tree *tree;
42 get_extent_t *get_extent;
44 /* tells writepage not to lock the state bits for this range
45 * it still does the unlocking
47 unsigned int extent_locked:1;
49 /* tells the submit_bio code to use a WRITE_SYNC */
50 unsigned int sync_io:1;
53 int __init extent_io_init(void)
55 extent_state_cache = kmem_cache_create("extent_state",
56 sizeof(struct extent_state), 0,
57 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
58 if (!extent_state_cache)
61 extent_buffer_cache = kmem_cache_create("extent_buffers",
62 sizeof(struct extent_buffer), 0,
63 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
64 if (!extent_buffer_cache)
65 goto free_state_cache;
69 kmem_cache_destroy(extent_state_cache);
73 void extent_io_exit(void)
75 struct extent_state *state;
76 struct extent_buffer *eb;
78 while (!list_empty(&states)) {
79 state = list_entry(states.next, struct extent_state, leak_list);
80 printk(KERN_ERR "btrfs state leak: start %llu end %llu "
81 "state %lu in tree %p refs %d\n",
82 (unsigned long long)state->start,
83 (unsigned long long)state->end,
84 state->state, state->tree, atomic_read(&state->refs));
85 list_del(&state->leak_list);
86 kmem_cache_free(extent_state_cache, state);
90 while (!list_empty(&buffers)) {
91 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
92 printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
93 "refs %d\n", (unsigned long long)eb->start,
94 eb->len, atomic_read(&eb->refs));
95 list_del(&eb->leak_list);
96 kmem_cache_free(extent_buffer_cache, eb);
98 if (extent_state_cache)
99 kmem_cache_destroy(extent_state_cache);
100 if (extent_buffer_cache)
101 kmem_cache_destroy(extent_buffer_cache);
104 void extent_io_tree_init(struct extent_io_tree *tree,
105 struct address_space *mapping, gfp_t mask)
107 tree->state.rb_node = NULL;
108 tree->buffer.rb_node = NULL;
110 tree->dirty_bytes = 0;
111 spin_lock_init(&tree->lock);
112 spin_lock_init(&tree->buffer_lock);
113 tree->mapping = mapping;
116 static struct extent_state *alloc_extent_state(gfp_t mask)
118 struct extent_state *state;
123 state = kmem_cache_alloc(extent_state_cache, mask);
130 spin_lock_irqsave(&leak_lock, flags);
131 list_add(&state->leak_list, &states);
132 spin_unlock_irqrestore(&leak_lock, flags);
134 atomic_set(&state->refs, 1);
135 init_waitqueue_head(&state->wq);
139 static void free_extent_state(struct extent_state *state)
143 if (atomic_dec_and_test(&state->refs)) {
147 WARN_ON(state->tree);
149 spin_lock_irqsave(&leak_lock, flags);
150 list_del(&state->leak_list);
151 spin_unlock_irqrestore(&leak_lock, flags);
153 kmem_cache_free(extent_state_cache, state);
157 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
158 struct rb_node *node)
160 struct rb_node **p = &root->rb_node;
161 struct rb_node *parent = NULL;
162 struct tree_entry *entry;
166 entry = rb_entry(parent, struct tree_entry, rb_node);
168 if (offset < entry->start)
170 else if (offset > entry->end)
176 entry = rb_entry(node, struct tree_entry, rb_node);
177 rb_link_node(node, parent, p);
178 rb_insert_color(node, root);
182 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
183 struct rb_node **prev_ret,
184 struct rb_node **next_ret)
186 struct rb_root *root = &tree->state;
187 struct rb_node *n = root->rb_node;
188 struct rb_node *prev = NULL;
189 struct rb_node *orig_prev = NULL;
190 struct tree_entry *entry;
191 struct tree_entry *prev_entry = NULL;
194 entry = rb_entry(n, struct tree_entry, rb_node);
198 if (offset < entry->start)
200 else if (offset > entry->end)
208 while (prev && offset > prev_entry->end) {
209 prev = rb_next(prev);
210 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
217 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
218 while (prev && offset < prev_entry->start) {
219 prev = rb_prev(prev);
220 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
227 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
230 struct rb_node *prev = NULL;
233 ret = __etree_search(tree, offset, &prev, NULL);
239 static struct extent_buffer *buffer_tree_insert(struct extent_io_tree *tree,
240 u64 offset, struct rb_node *node)
242 struct rb_root *root = &tree->buffer;
243 struct rb_node **p = &root->rb_node;
244 struct rb_node *parent = NULL;
245 struct extent_buffer *eb;
249 eb = rb_entry(parent, struct extent_buffer, rb_node);
251 if (offset < eb->start)
253 else if (offset > eb->start)
259 rb_link_node(node, parent, p);
260 rb_insert_color(node, root);
264 static struct extent_buffer *buffer_search(struct extent_io_tree *tree,
267 struct rb_root *root = &tree->buffer;
268 struct rb_node *n = root->rb_node;
269 struct extent_buffer *eb;
272 eb = rb_entry(n, struct extent_buffer, rb_node);
273 if (offset < eb->start)
275 else if (offset > eb->start)
284 * utility function to look for merge candidates inside a given range.
285 * Any extents with matching state are merged together into a single
286 * extent in the tree. Extents with EXTENT_IO in their state field
287 * are not merged because the end_io handlers need to be able to do
288 * operations on them without sleeping (or doing allocations/splits).
290 * This should be called with the tree lock held.
292 static int merge_state(struct extent_io_tree *tree,
293 struct extent_state *state)
295 struct extent_state *other;
296 struct rb_node *other_node;
298 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
301 other_node = rb_prev(&state->rb_node);
303 other = rb_entry(other_node, struct extent_state, rb_node);
304 if (other->end == state->start - 1 &&
305 other->state == state->state) {
306 state->start = other->start;
308 rb_erase(&other->rb_node, &tree->state);
309 free_extent_state(other);
312 other_node = rb_next(&state->rb_node);
314 other = rb_entry(other_node, struct extent_state, rb_node);
315 if (other->start == state->end + 1 &&
316 other->state == state->state) {
317 other->start = state->start;
319 rb_erase(&state->rb_node, &tree->state);
320 free_extent_state(state);
326 static void set_state_cb(struct extent_io_tree *tree,
327 struct extent_state *state,
330 if (tree->ops && tree->ops->set_bit_hook) {
331 tree->ops->set_bit_hook(tree->mapping->host, state->start,
332 state->end, state->state, bits);
336 static void clear_state_cb(struct extent_io_tree *tree,
337 struct extent_state *state,
340 if (tree->ops && tree->ops->clear_bit_hook) {
341 tree->ops->clear_bit_hook(tree->mapping->host, state->start,
342 state->end, state->state, bits);
347 * insert an extent_state struct into the tree. 'bits' are set on the
348 * struct before it is inserted.
350 * This may return -EEXIST if the extent is already there, in which case the
351 * state struct is freed.
353 * The tree lock is not taken internally. This is a utility function and
354 * probably isn't what you want to call (see set/clear_extent_bit).
356 static int insert_state(struct extent_io_tree *tree,
357 struct extent_state *state, u64 start, u64 end,
360 struct rb_node *node;
363 printk(KERN_ERR "btrfs end < start %llu %llu\n",
364 (unsigned long long)end,
365 (unsigned long long)start);
368 if (bits & EXTENT_DIRTY)
369 tree->dirty_bytes += end - start + 1;
370 state->start = start;
372 set_state_cb(tree, state, bits);
373 state->state |= bits;
374 node = tree_insert(&tree->state, end, &state->rb_node);
376 struct extent_state *found;
377 found = rb_entry(node, struct extent_state, rb_node);
378 printk(KERN_ERR "btrfs found node %llu %llu on insert of "
379 "%llu %llu\n", (unsigned long long)found->start,
380 (unsigned long long)found->end,
381 (unsigned long long)start, (unsigned long long)end);
382 free_extent_state(state);
386 merge_state(tree, state);
391 * split a given extent state struct in two, inserting the preallocated
392 * struct 'prealloc' as the newly created second half. 'split' indicates an
393 * offset inside 'orig' where it should be split.
396 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
397 * are two extent state structs in the tree:
398 * prealloc: [orig->start, split - 1]
399 * orig: [ split, orig->end ]
401 * The tree locks are not taken by this function. They need to be held
404 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
405 struct extent_state *prealloc, u64 split)
407 struct rb_node *node;
408 prealloc->start = orig->start;
409 prealloc->end = split - 1;
410 prealloc->state = orig->state;
413 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
415 free_extent_state(prealloc);
418 prealloc->tree = tree;
423 * utility function to clear some bits in an extent state struct.
424 * it will optionally wake up any one waiting on this state (wake == 1), or
425 * forcibly remove the state from the tree (delete == 1).
427 * If no bits are set on the state struct after clearing things, the
428 * struct is freed and removed from the tree
430 static int clear_state_bit(struct extent_io_tree *tree,
431 struct extent_state *state, int bits, int wake,
434 int ret = state->state & bits;
436 if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
437 u64 range = state->end - state->start + 1;
438 WARN_ON(range > tree->dirty_bytes);
439 tree->dirty_bytes -= range;
441 clear_state_cb(tree, state, bits);
442 state->state &= ~bits;
445 if (delete || state->state == 0) {
447 clear_state_cb(tree, state, state->state);
448 rb_erase(&state->rb_node, &tree->state);
450 free_extent_state(state);
455 merge_state(tree, state);
461 * clear some bits on a range in the tree. This may require splitting
462 * or inserting elements in the tree, so the gfp mask is used to
463 * indicate which allocations or sleeping are allowed.
465 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
466 * the given range from the tree regardless of state (ie for truncate).
468 * the range [start, end] is inclusive.
470 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
471 * bits were already set, or zero if none of the bits were already set.
473 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
474 int bits, int wake, int delete,
475 struct extent_state **cached_state,
478 struct extent_state *state;
479 struct extent_state *cached;
480 struct extent_state *prealloc = NULL;
481 struct rb_node *next_node;
482 struct rb_node *node;
488 if (!prealloc && (mask & __GFP_WAIT)) {
489 prealloc = alloc_extent_state(mask);
494 spin_lock(&tree->lock);
496 cached = *cached_state;
497 *cached_state = NULL;
498 if (cached->tree && cached->start == start) {
499 atomic_dec(&cached->refs);
501 last_end = state->end;
504 free_extent_state(cached);
507 * this search will find the extents that end after
510 node = tree_search(tree, start);
513 state = rb_entry(node, struct extent_state, rb_node);
515 if (state->start > end)
517 WARN_ON(state->end < start);
518 last_end = state->end;
521 * | ---- desired range ---- |
523 * | ------------- state -------------- |
525 * We need to split the extent we found, and may flip
526 * bits on second half.
528 * If the extent we found extends past our range, we
529 * just split and search again. It'll get split again
530 * the next time though.
532 * If the extent we found is inside our range, we clear
533 * the desired bit on it.
536 if (state->start < start) {
538 prealloc = alloc_extent_state(GFP_ATOMIC);
539 err = split_state(tree, state, prealloc, start);
540 BUG_ON(err == -EEXIST);
544 if (state->end <= end) {
545 set |= clear_state_bit(tree, state, bits,
547 if (last_end == (u64)-1)
549 start = last_end + 1;
551 start = state->start;
556 * | ---- desired range ---- |
558 * We need to split the extent, and clear the bit
561 if (state->start <= end && state->end > end) {
563 prealloc = alloc_extent_state(GFP_ATOMIC);
564 err = split_state(tree, state, prealloc, end + 1);
565 BUG_ON(err == -EEXIST);
569 set |= clear_state_bit(tree, prealloc, bits,
575 if (state->end < end && prealloc && !need_resched())
576 next_node = rb_next(&state->rb_node);
579 set |= clear_state_bit(tree, state, bits, wake, delete);
580 if (last_end == (u64)-1)
582 start = last_end + 1;
583 if (start <= end && next_node) {
584 state = rb_entry(next_node, struct extent_state,
586 if (state->start == start)
592 spin_unlock(&tree->lock);
594 free_extent_state(prealloc);
601 spin_unlock(&tree->lock);
602 if (mask & __GFP_WAIT)
607 static int wait_on_state(struct extent_io_tree *tree,
608 struct extent_state *state)
609 __releases(tree->lock)
610 __acquires(tree->lock)
613 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
614 spin_unlock(&tree->lock);
616 spin_lock(&tree->lock);
617 finish_wait(&state->wq, &wait);
622 * waits for one or more bits to clear on a range in the state tree.
623 * The range [start, end] is inclusive.
624 * The tree lock is taken by this function
626 int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
628 struct extent_state *state;
629 struct rb_node *node;
631 spin_lock(&tree->lock);
635 * this search will find all the extents that end after
638 node = tree_search(tree, start);
642 state = rb_entry(node, struct extent_state, rb_node);
644 if (state->start > end)
647 if (state->state & bits) {
648 start = state->start;
649 atomic_inc(&state->refs);
650 wait_on_state(tree, state);
651 free_extent_state(state);
654 start = state->end + 1;
659 if (need_resched()) {
660 spin_unlock(&tree->lock);
662 spin_lock(&tree->lock);
666 spin_unlock(&tree->lock);
670 static void set_state_bits(struct extent_io_tree *tree,
671 struct extent_state *state,
674 if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
675 u64 range = state->end - state->start + 1;
676 tree->dirty_bytes += range;
678 set_state_cb(tree, state, bits);
679 state->state |= bits;
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 static 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,
709 struct extent_state *state;
710 struct extent_state *prealloc = NULL;
711 struct rb_node *node;
716 if (!prealloc && (mask & __GFP_WAIT)) {
717 prealloc = alloc_extent_state(mask);
722 spin_lock(&tree->lock);
723 if (cached_state && *cached_state) {
724 state = *cached_state;
725 if (state->start == start && state->tree) {
726 node = &state->rb_node;
731 * this search will find all the extents that end after
734 node = tree_search(tree, start);
736 err = insert_state(tree, prealloc, start, end, bits);
738 BUG_ON(err == -EEXIST);
741 state = rb_entry(node, struct extent_state, rb_node);
743 last_start = state->start;
744 last_end = state->end;
747 * | ---- desired range ---- |
750 * Just lock what we found and keep going
752 if (state->start == start && state->end <= end) {
753 struct rb_node *next_node;
754 if (state->state & exclusive_bits) {
755 *failed_start = state->start;
759 set_state_bits(tree, state, bits);
760 cache_state(state, cached_state);
761 merge_state(tree, state);
762 if (last_end == (u64)-1)
765 start = last_end + 1;
766 if (start < end && prealloc && !need_resched()) {
767 next_node = rb_next(node);
769 state = rb_entry(next_node, struct extent_state,
771 if (state->start == start)
779 * | ---- desired range ---- |
782 * | ------------- state -------------- |
784 * We need to split the extent we found, and may flip bits on
787 * If the extent we found extends past our
788 * range, we just split and search again. It'll get split
789 * again the next time though.
791 * If the extent we found is inside our range, we set the
794 if (state->start < start) {
795 if (state->state & exclusive_bits) {
796 *failed_start = start;
800 err = split_state(tree, state, prealloc, start);
801 BUG_ON(err == -EEXIST);
805 if (state->end <= end) {
806 set_state_bits(tree, state, bits);
807 cache_state(state, cached_state);
808 merge_state(tree, state);
809 if (last_end == (u64)-1)
811 start = last_end + 1;
813 start = state->start;
818 * | ---- desired range ---- |
819 * | state | or | state |
821 * There's a hole, we need to insert something in it and
822 * ignore the extent we found.
824 if (state->start > start) {
826 if (end < last_start)
829 this_end = last_start - 1;
830 err = insert_state(tree, prealloc, start, this_end,
832 cache_state(prealloc, cached_state);
834 BUG_ON(err == -EEXIST);
837 start = this_end + 1;
841 * | ---- desired range ---- |
843 * We need to split the extent, and set the bit
846 if (state->start <= end && state->end > end) {
847 if (state->state & exclusive_bits) {
848 *failed_start = start;
852 err = split_state(tree, state, prealloc, end + 1);
853 BUG_ON(err == -EEXIST);
855 set_state_bits(tree, prealloc, bits);
856 cache_state(prealloc, cached_state);
857 merge_state(tree, prealloc);
865 spin_unlock(&tree->lock);
867 free_extent_state(prealloc);
874 spin_unlock(&tree->lock);
875 if (mask & __GFP_WAIT)
880 /* wrappers around set/clear extent bit */
881 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
884 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
888 int set_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
891 return set_extent_bit(tree, start, end, EXTENT_ORDERED, 0, NULL, NULL,
895 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
896 int bits, gfp_t mask)
898 return set_extent_bit(tree, start, end, bits, 0, NULL,
902 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
903 int bits, gfp_t mask)
905 return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
908 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
911 return set_extent_bit(tree, start, end,
912 EXTENT_DELALLOC | EXTENT_DIRTY | EXTENT_UPTODATE,
913 0, NULL, NULL, mask);
916 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
919 return clear_extent_bit(tree, start, end,
920 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
924 int clear_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
927 return clear_extent_bit(tree, start, end, EXTENT_ORDERED, 1, 0,
931 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
934 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
938 static int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
941 return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0,
945 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
948 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
952 static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
955 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
959 int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end)
961 return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
965 * either insert or lock state struct between start and end use mask to tell
966 * us if waiting is desired.
968 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
969 int bits, struct extent_state **cached_state, gfp_t mask)
974 err = set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
975 EXTENT_LOCKED, &failed_start,
977 if (err == -EEXIST && (mask & __GFP_WAIT)) {
978 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
979 start = failed_start;
983 WARN_ON(start > end);
988 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
990 return lock_extent_bits(tree, start, end, 0, NULL, mask);
993 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
999 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1000 &failed_start, NULL, mask);
1001 if (err == -EEXIST) {
1002 if (failed_start > start)
1003 clear_extent_bit(tree, start, failed_start - 1,
1004 EXTENT_LOCKED, 1, 0, NULL, mask);
1010 int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
1011 struct extent_state **cached, gfp_t mask)
1013 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
1017 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
1020 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
1025 * helper function to set pages and extents in the tree dirty
1027 int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end)
1029 unsigned long index = start >> PAGE_CACHE_SHIFT;
1030 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1033 while (index <= end_index) {
1034 page = find_get_page(tree->mapping, index);
1036 __set_page_dirty_nobuffers(page);
1037 page_cache_release(page);
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)
1142 struct rb_node *node;
1143 struct extent_state *state;
1144 u64 cur_start = *start;
1146 u64 total_bytes = 0;
1148 spin_lock(&tree->lock);
1151 * this search will find all the extents that end after
1154 node = tree_search(tree, cur_start);
1162 state = rb_entry(node, struct extent_state, rb_node);
1163 if (found && (state->start != cur_start ||
1164 (state->state & EXTENT_BOUNDARY))) {
1167 if (!(state->state & EXTENT_DELALLOC)) {
1173 *start = state->start;
1176 cur_start = state->end + 1;
1177 node = rb_next(node);
1180 total_bytes += state->end - state->start + 1;
1181 if (total_bytes >= max_bytes)
1185 spin_unlock(&tree->lock);
1189 static noinline int __unlock_for_delalloc(struct inode *inode,
1190 struct page *locked_page,
1194 struct page *pages[16];
1195 unsigned long index = start >> PAGE_CACHE_SHIFT;
1196 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1197 unsigned long nr_pages = end_index - index + 1;
1200 if (index == locked_page->index && end_index == index)
1203 while (nr_pages > 0) {
1204 ret = find_get_pages_contig(inode->i_mapping, index,
1205 min_t(unsigned long, nr_pages,
1206 ARRAY_SIZE(pages)), pages);
1207 for (i = 0; i < ret; i++) {
1208 if (pages[i] != locked_page)
1209 unlock_page(pages[i]);
1210 page_cache_release(pages[i]);
1219 static noinline int lock_delalloc_pages(struct inode *inode,
1220 struct page *locked_page,
1224 unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
1225 unsigned long start_index = index;
1226 unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
1227 unsigned long pages_locked = 0;
1228 struct page *pages[16];
1229 unsigned long nrpages;
1233 /* the caller is responsible for locking the start index */
1234 if (index == locked_page->index && index == end_index)
1237 /* skip the page at the start index */
1238 nrpages = end_index - index + 1;
1239 while (nrpages > 0) {
1240 ret = find_get_pages_contig(inode->i_mapping, index,
1241 min_t(unsigned long,
1242 nrpages, ARRAY_SIZE(pages)), pages);
1247 /* now we have an array of pages, lock them all */
1248 for (i = 0; i < ret; i++) {
1250 * the caller is taking responsibility for
1253 if (pages[i] != locked_page) {
1254 lock_page(pages[i]);
1255 if (!PageDirty(pages[i]) ||
1256 pages[i]->mapping != inode->i_mapping) {
1258 unlock_page(pages[i]);
1259 page_cache_release(pages[i]);
1263 page_cache_release(pages[i]);
1272 if (ret && pages_locked) {
1273 __unlock_for_delalloc(inode, locked_page,
1275 ((u64)(start_index + pages_locked - 1)) <<
1282 * find a contiguous range of bytes in the file marked as delalloc, not
1283 * more than 'max_bytes'. start and end are used to return the range,
1285 * 1 is returned if we find something, 0 if nothing was in the tree
1287 static noinline u64 find_lock_delalloc_range(struct inode *inode,
1288 struct extent_io_tree *tree,
1289 struct page *locked_page,
1290 u64 *start, u64 *end,
1296 struct extent_state *cached_state = NULL;
1301 /* step one, find a bunch of delalloc bytes starting at start */
1302 delalloc_start = *start;
1304 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1306 if (!found || delalloc_end <= *start) {
1307 *start = delalloc_start;
1308 *end = delalloc_end;
1313 * start comes from the offset of locked_page. We have to lock
1314 * pages in order, so we can't process delalloc bytes before
1317 if (delalloc_start < *start)
1318 delalloc_start = *start;
1321 * make sure to limit the number of pages we try to lock down
1324 if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1325 delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
1327 /* step two, lock all the pages after the page that has start */
1328 ret = lock_delalloc_pages(inode, locked_page,
1329 delalloc_start, delalloc_end);
1330 if (ret == -EAGAIN) {
1331 /* some of the pages are gone, lets avoid looping by
1332 * shortening the size of the delalloc range we're searching
1334 free_extent_state(cached_state);
1336 unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
1337 max_bytes = PAGE_CACHE_SIZE - offset;
1347 /* step three, lock the state bits for the whole range */
1348 lock_extent_bits(tree, delalloc_start, delalloc_end,
1349 0, &cached_state, GFP_NOFS);
1351 /* then test to make sure it is all still delalloc */
1352 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1353 EXTENT_DELALLOC, 1, cached_state);
1355 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1356 &cached_state, GFP_NOFS);
1357 __unlock_for_delalloc(inode, locked_page,
1358 delalloc_start, delalloc_end);
1362 free_extent_state(cached_state);
1363 *start = delalloc_start;
1364 *end = delalloc_end;
1369 int extent_clear_unlock_delalloc(struct inode *inode,
1370 struct extent_io_tree *tree,
1371 u64 start, u64 end, struct page *locked_page,
1374 int clear_delalloc, int clear_dirty,
1379 struct page *pages[16];
1380 unsigned long index = start >> PAGE_CACHE_SHIFT;
1381 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1382 unsigned long nr_pages = end_index - index + 1;
1387 clear_bits |= EXTENT_LOCKED;
1389 clear_bits |= EXTENT_DIRTY;
1392 clear_bits |= EXTENT_DELALLOC;
1394 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1395 if (!(unlock_pages || clear_dirty || set_writeback || end_writeback))
1398 while (nr_pages > 0) {
1399 ret = find_get_pages_contig(inode->i_mapping, index,
1400 min_t(unsigned long,
1401 nr_pages, ARRAY_SIZE(pages)), pages);
1402 for (i = 0; i < ret; i++) {
1403 if (pages[i] == locked_page) {
1404 page_cache_release(pages[i]);
1408 clear_page_dirty_for_io(pages[i]);
1410 set_page_writeback(pages[i]);
1412 end_page_writeback(pages[i]);
1414 unlock_page(pages[i]);
1415 page_cache_release(pages[i]);
1425 * count the number of bytes in the tree that have a given bit(s)
1426 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1427 * cached. The total number found is returned.
1429 u64 count_range_bits(struct extent_io_tree *tree,
1430 u64 *start, u64 search_end, u64 max_bytes,
1433 struct rb_node *node;
1434 struct extent_state *state;
1435 u64 cur_start = *start;
1436 u64 total_bytes = 0;
1439 if (search_end <= cur_start) {
1444 spin_lock(&tree->lock);
1445 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1446 total_bytes = tree->dirty_bytes;
1450 * this search will find all the extents that end after
1453 node = tree_search(tree, cur_start);
1458 state = rb_entry(node, struct extent_state, rb_node);
1459 if (state->start > search_end)
1461 if (state->end >= cur_start && (state->state & bits)) {
1462 total_bytes += min(search_end, state->end) + 1 -
1463 max(cur_start, state->start);
1464 if (total_bytes >= max_bytes)
1467 *start = state->start;
1471 node = rb_next(node);
1476 spin_unlock(&tree->lock);
1481 * set the private field for a given byte offset in the tree. If there isn't
1482 * an extent_state there already, this does nothing.
1484 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1486 struct rb_node *node;
1487 struct extent_state *state;
1490 spin_lock(&tree->lock);
1492 * this search will find all the extents that end after
1495 node = tree_search(tree, start);
1500 state = rb_entry(node, struct extent_state, rb_node);
1501 if (state->start != start) {
1505 state->private = private;
1507 spin_unlock(&tree->lock);
1511 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1513 struct rb_node *node;
1514 struct extent_state *state;
1517 spin_lock(&tree->lock);
1519 * this search will find all the extents that end after
1522 node = tree_search(tree, start);
1527 state = rb_entry(node, struct extent_state, rb_node);
1528 if (state->start != start) {
1532 *private = state->private;
1534 spin_unlock(&tree->lock);
1539 * searches a range in the state tree for a given mask.
1540 * If 'filled' == 1, this returns 1 only if every extent in the tree
1541 * has the bits set. Otherwise, 1 is returned if any bit in the
1542 * range is found set.
1544 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1545 int bits, int filled, struct extent_state *cached)
1547 struct extent_state *state = NULL;
1548 struct rb_node *node;
1551 spin_lock(&tree->lock);
1552 if (cached && cached->tree && cached->start == start)
1553 node = &cached->rb_node;
1555 node = tree_search(tree, start);
1556 while (node && start <= end) {
1557 state = rb_entry(node, struct extent_state, rb_node);
1559 if (filled && state->start > start) {
1564 if (state->start > end)
1567 if (state->state & bits) {
1571 } else if (filled) {
1575 start = state->end + 1;
1578 node = rb_next(node);
1585 spin_unlock(&tree->lock);
1590 * helper function to set a given page up to date if all the
1591 * extents in the tree for that page are up to date
1593 static int check_page_uptodate(struct extent_io_tree *tree,
1596 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1597 u64 end = start + PAGE_CACHE_SIZE - 1;
1598 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1599 SetPageUptodate(page);
1604 * helper function to unlock a page if all the extents in the tree
1605 * for that page are unlocked
1607 static int check_page_locked(struct extent_io_tree *tree,
1610 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1611 u64 end = start + PAGE_CACHE_SIZE - 1;
1612 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
1618 * helper function to end page writeback if all the extents
1619 * in the tree for that page are done with writeback
1621 static int check_page_writeback(struct extent_io_tree *tree,
1624 end_page_writeback(page);
1628 /* lots and lots of room for performance fixes in the end_bio funcs */
1631 * after a writepage IO is done, we need to:
1632 * clear the uptodate bits on error
1633 * clear the writeback bits in the extent tree for this IO
1634 * end_page_writeback if the page has no more pending IO
1636 * Scheduling is not allowed, so the extent state tree is expected
1637 * to have one and only one object corresponding to this IO.
1639 static void end_bio_extent_writepage(struct bio *bio, int err)
1641 int uptodate = err == 0;
1642 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1643 struct extent_io_tree *tree;
1650 struct page *page = bvec->bv_page;
1651 tree = &BTRFS_I(page->mapping->host)->io_tree;
1653 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1655 end = start + bvec->bv_len - 1;
1657 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1662 if (--bvec >= bio->bi_io_vec)
1663 prefetchw(&bvec->bv_page->flags);
1664 if (tree->ops && tree->ops->writepage_end_io_hook) {
1665 ret = tree->ops->writepage_end_io_hook(page, start,
1666 end, NULL, uptodate);
1671 if (!uptodate && tree->ops &&
1672 tree->ops->writepage_io_failed_hook) {
1673 ret = tree->ops->writepage_io_failed_hook(bio, page,
1676 uptodate = (err == 0);
1682 clear_extent_uptodate(tree, start, end, GFP_NOFS);
1683 ClearPageUptodate(page);
1688 end_page_writeback(page);
1690 check_page_writeback(tree, page);
1691 } while (bvec >= bio->bi_io_vec);
1697 * after a readpage IO is done, we need to:
1698 * clear the uptodate bits on error
1699 * set the uptodate bits if things worked
1700 * set the page up to date if all extents in the tree are uptodate
1701 * clear the lock bit in the extent tree
1702 * unlock the page if there are no other extents locked for it
1704 * Scheduling is not allowed, so the extent state tree is expected
1705 * to have one and only one object corresponding to this IO.
1707 static void end_bio_extent_readpage(struct bio *bio, int err)
1709 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1710 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1711 struct extent_io_tree *tree;
1721 struct page *page = bvec->bv_page;
1722 tree = &BTRFS_I(page->mapping->host)->io_tree;
1724 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1726 end = start + bvec->bv_len - 1;
1728 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1733 if (--bvec >= bio->bi_io_vec)
1734 prefetchw(&bvec->bv_page->flags);
1736 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
1737 ret = tree->ops->readpage_end_io_hook(page, start, end,
1742 if (!uptodate && tree->ops &&
1743 tree->ops->readpage_io_failed_hook) {
1744 ret = tree->ops->readpage_io_failed_hook(bio, page,
1748 test_bit(BIO_UPTODATE, &bio->bi_flags);
1756 set_extent_uptodate(tree, start, end,
1759 unlock_extent(tree, start, end, GFP_ATOMIC);
1763 SetPageUptodate(page);
1765 ClearPageUptodate(page);
1771 check_page_uptodate(tree, page);
1773 ClearPageUptodate(page);
1776 check_page_locked(tree, page);
1778 } while (bvec >= bio->bi_io_vec);
1784 * IO done from prepare_write is pretty simple, we just unlock
1785 * the structs in the extent tree when done, and set the uptodate bits
1788 static void end_bio_extent_preparewrite(struct bio *bio, int err)
1790 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1791 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1792 struct extent_io_tree *tree;
1797 struct page *page = bvec->bv_page;
1798 tree = &BTRFS_I(page->mapping->host)->io_tree;
1800 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1802 end = start + bvec->bv_len - 1;
1804 if (--bvec >= bio->bi_io_vec)
1805 prefetchw(&bvec->bv_page->flags);
1808 set_extent_uptodate(tree, start, end, GFP_ATOMIC);
1810 ClearPageUptodate(page);
1814 unlock_extent(tree, start, end, GFP_ATOMIC);
1816 } while (bvec >= bio->bi_io_vec);
1822 extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
1827 bio = bio_alloc(gfp_flags, nr_vecs);
1829 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
1830 while (!bio && (nr_vecs /= 2))
1831 bio = bio_alloc(gfp_flags, nr_vecs);
1836 bio->bi_bdev = bdev;
1837 bio->bi_sector = first_sector;
1842 static int submit_one_bio(int rw, struct bio *bio, int mirror_num,
1843 unsigned long bio_flags)
1846 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1847 struct page *page = bvec->bv_page;
1848 struct extent_io_tree *tree = bio->bi_private;
1852 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
1853 end = start + bvec->bv_len - 1;
1855 bio->bi_private = NULL;
1859 if (tree->ops && tree->ops->submit_bio_hook)
1860 tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
1861 mirror_num, bio_flags);
1863 submit_bio(rw, bio);
1864 if (bio_flagged(bio, BIO_EOPNOTSUPP))
1870 static int submit_extent_page(int rw, struct extent_io_tree *tree,
1871 struct page *page, sector_t sector,
1872 size_t size, unsigned long offset,
1873 struct block_device *bdev,
1874 struct bio **bio_ret,
1875 unsigned long max_pages,
1876 bio_end_io_t end_io_func,
1878 unsigned long prev_bio_flags,
1879 unsigned long bio_flags)
1885 int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
1886 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
1887 size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
1889 if (bio_ret && *bio_ret) {
1892 contig = bio->bi_sector == sector;
1894 contig = bio->bi_sector + (bio->bi_size >> 9) ==
1897 if (prev_bio_flags != bio_flags || !contig ||
1898 (tree->ops && tree->ops->merge_bio_hook &&
1899 tree->ops->merge_bio_hook(page, offset, page_size, bio,
1901 bio_add_page(bio, page, page_size, offset) < page_size) {
1902 ret = submit_one_bio(rw, bio, mirror_num,
1909 if (this_compressed)
1912 nr = bio_get_nr_vecs(bdev);
1914 bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
1916 bio_add_page(bio, page, page_size, offset);
1917 bio->bi_end_io = end_io_func;
1918 bio->bi_private = tree;
1923 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
1928 void set_page_extent_mapped(struct page *page)
1930 if (!PagePrivate(page)) {
1931 SetPagePrivate(page);
1932 page_cache_get(page);
1933 set_page_private(page, EXTENT_PAGE_PRIVATE);
1937 static void set_page_extent_head(struct page *page, unsigned long len)
1939 set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
1943 * basic readpage implementation. Locked extent state structs are inserted
1944 * into the tree that are removed when the IO is done (by the end_io
1947 static int __extent_read_full_page(struct extent_io_tree *tree,
1949 get_extent_t *get_extent,
1950 struct bio **bio, int mirror_num,
1951 unsigned long *bio_flags)
1953 struct inode *inode = page->mapping->host;
1954 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1955 u64 page_end = start + PAGE_CACHE_SIZE - 1;
1959 u64 last_byte = i_size_read(inode);
1963 struct extent_map *em;
1964 struct block_device *bdev;
1967 size_t page_offset = 0;
1969 size_t disk_io_size;
1970 size_t blocksize = inode->i_sb->s_blocksize;
1971 unsigned long this_bio_flag = 0;
1973 set_page_extent_mapped(page);
1976 lock_extent(tree, start, end, GFP_NOFS);
1978 if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
1980 size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
1983 iosize = PAGE_CACHE_SIZE - zero_offset;
1984 userpage = kmap_atomic(page, KM_USER0);
1985 memset(userpage + zero_offset, 0, iosize);
1986 flush_dcache_page(page);
1987 kunmap_atomic(userpage, KM_USER0);
1990 while (cur <= end) {
1991 if (cur >= last_byte) {
1993 iosize = PAGE_CACHE_SIZE - page_offset;
1994 userpage = kmap_atomic(page, KM_USER0);
1995 memset(userpage + page_offset, 0, iosize);
1996 flush_dcache_page(page);
1997 kunmap_atomic(userpage, KM_USER0);
1998 set_extent_uptodate(tree, cur, cur + iosize - 1,
2000 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2003 em = get_extent(inode, page, page_offset, cur,
2005 if (IS_ERR(em) || !em) {
2007 unlock_extent(tree, cur, end, GFP_NOFS);
2010 extent_offset = cur - em->start;
2011 BUG_ON(extent_map_end(em) <= cur);
2014 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
2015 this_bio_flag = EXTENT_BIO_COMPRESSED;
2017 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2018 cur_end = min(extent_map_end(em) - 1, end);
2019 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2020 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2021 disk_io_size = em->block_len;
2022 sector = em->block_start >> 9;
2024 sector = (em->block_start + extent_offset) >> 9;
2025 disk_io_size = iosize;
2028 block_start = em->block_start;
2029 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2030 block_start = EXTENT_MAP_HOLE;
2031 free_extent_map(em);
2034 /* we've found a hole, just zero and go on */
2035 if (block_start == EXTENT_MAP_HOLE) {
2037 userpage = kmap_atomic(page, KM_USER0);
2038 memset(userpage + page_offset, 0, iosize);
2039 flush_dcache_page(page);
2040 kunmap_atomic(userpage, KM_USER0);
2042 set_extent_uptodate(tree, cur, cur + iosize - 1,
2044 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2046 page_offset += iosize;
2049 /* the get_extent function already copied into the page */
2050 if (test_range_bit(tree, cur, cur_end,
2051 EXTENT_UPTODATE, 1, NULL)) {
2052 check_page_uptodate(tree, page);
2053 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2055 page_offset += iosize;
2058 /* we have an inline extent but it didn't get marked up
2059 * to date. Error out
2061 if (block_start == EXTENT_MAP_INLINE) {
2063 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2065 page_offset += iosize;
2070 if (tree->ops && tree->ops->readpage_io_hook) {
2071 ret = tree->ops->readpage_io_hook(page, cur,
2075 unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
2077 ret = submit_extent_page(READ, tree, page,
2078 sector, disk_io_size, page_offset,
2080 end_bio_extent_readpage, mirror_num,
2084 *bio_flags = this_bio_flag;
2089 page_offset += iosize;
2092 if (!PageError(page))
2093 SetPageUptodate(page);
2099 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
2100 get_extent_t *get_extent)
2102 struct bio *bio = NULL;
2103 unsigned long bio_flags = 0;
2106 ret = __extent_read_full_page(tree, page, get_extent, &bio, 0,
2109 submit_one_bio(READ, bio, 0, bio_flags);
2113 static noinline void update_nr_written(struct page *page,
2114 struct writeback_control *wbc,
2115 unsigned long nr_written)
2117 wbc->nr_to_write -= nr_written;
2118 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
2119 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
2120 page->mapping->writeback_index = page->index + nr_written;
2124 * the writepage semantics are similar to regular writepage. extent
2125 * records are inserted to lock ranges in the tree, and as dirty areas
2126 * are found, they are marked writeback. Then the lock bits are removed
2127 * and the end_io handler clears the writeback ranges
2129 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
2132 struct inode *inode = page->mapping->host;
2133 struct extent_page_data *epd = data;
2134 struct extent_io_tree *tree = epd->tree;
2135 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2137 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2141 u64 last_byte = i_size_read(inode);
2146 struct extent_state *cached_state = NULL;
2147 struct extent_map *em;
2148 struct block_device *bdev;
2151 size_t pg_offset = 0;
2153 loff_t i_size = i_size_read(inode);
2154 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
2160 unsigned long nr_written = 0;
2162 if (wbc->sync_mode == WB_SYNC_ALL)
2163 write_flags = WRITE_SYNC_PLUG;
2165 write_flags = WRITE;
2167 WARN_ON(!PageLocked(page));
2168 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2169 if (page->index > end_index ||
2170 (page->index == end_index && !pg_offset)) {
2171 page->mapping->a_ops->invalidatepage(page, 0);
2176 if (page->index == end_index) {
2179 userpage = kmap_atomic(page, KM_USER0);
2180 memset(userpage + pg_offset, 0,
2181 PAGE_CACHE_SIZE - pg_offset);
2182 kunmap_atomic(userpage, KM_USER0);
2183 flush_dcache_page(page);
2187 set_page_extent_mapped(page);
2189 delalloc_start = start;
2192 if (!epd->extent_locked) {
2193 u64 delalloc_to_write;
2195 * make sure the wbc mapping index is at least updated
2198 update_nr_written(page, wbc, 0);
2200 while (delalloc_end < page_end) {
2201 nr_delalloc = find_lock_delalloc_range(inode, tree,
2206 if (nr_delalloc == 0) {
2207 delalloc_start = delalloc_end + 1;
2210 tree->ops->fill_delalloc(inode, page, delalloc_start,
2211 delalloc_end, &page_started,
2213 delalloc_to_write = (delalloc_end -
2214 max_t(u64, page_offset(page),
2215 delalloc_start) + 1) >>
2217 if (wbc->nr_to_write < delalloc_to_write) {
2218 wbc->nr_to_write = min_t(long, 8192,
2221 delalloc_start = delalloc_end + 1;
2224 /* did the fill delalloc function already unlock and start
2230 * we've unlocked the page, so we can't update
2231 * the mapping's writeback index, just update
2234 wbc->nr_to_write -= nr_written;
2238 if (tree->ops && tree->ops->writepage_start_hook) {
2239 ret = tree->ops->writepage_start_hook(page, start,
2241 if (ret == -EAGAIN) {
2242 redirty_page_for_writepage(wbc, page);
2243 update_nr_written(page, wbc, nr_written);
2251 * we don't want to touch the inode after unlocking the page,
2252 * so we update the mapping writeback index now
2254 update_nr_written(page, wbc, nr_written + 1);
2257 if (last_byte <= start) {
2258 if (tree->ops && tree->ops->writepage_end_io_hook)
2259 tree->ops->writepage_end_io_hook(page, start,
2261 unlock_start = page_end + 1;
2265 blocksize = inode->i_sb->s_blocksize;
2267 while (cur <= end) {
2268 if (cur >= last_byte) {
2269 if (tree->ops && tree->ops->writepage_end_io_hook)
2270 tree->ops->writepage_end_io_hook(page, cur,
2272 unlock_start = page_end + 1;
2275 em = epd->get_extent(inode, page, pg_offset, cur,
2277 if (IS_ERR(em) || !em) {
2282 extent_offset = cur - em->start;
2283 BUG_ON(extent_map_end(em) <= cur);
2285 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2286 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2287 sector = (em->block_start + extent_offset) >> 9;
2289 block_start = em->block_start;
2290 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
2291 free_extent_map(em);
2295 * compressed and inline extents are written through other
2298 if (compressed || block_start == EXTENT_MAP_HOLE ||
2299 block_start == EXTENT_MAP_INLINE) {
2301 * end_io notification does not happen here for
2302 * compressed extents
2304 if (!compressed && tree->ops &&
2305 tree->ops->writepage_end_io_hook)
2306 tree->ops->writepage_end_io_hook(page, cur,
2309 else if (compressed) {
2310 /* we don't want to end_page_writeback on
2311 * a compressed extent. this happens
2318 pg_offset += iosize;
2322 /* leave this out until we have a page_mkwrite call */
2323 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
2324 EXTENT_DIRTY, 0, NULL)) {
2326 pg_offset += iosize;
2330 if (tree->ops && tree->ops->writepage_io_hook) {
2331 ret = tree->ops->writepage_io_hook(page, cur,
2339 unsigned long max_nr = end_index + 1;
2341 set_range_writeback(tree, cur, cur + iosize - 1);
2342 if (!PageWriteback(page)) {
2343 printk(KERN_ERR "btrfs warning page %lu not "
2344 "writeback, cur %llu end %llu\n",
2345 page->index, (unsigned long long)cur,
2346 (unsigned long long)end);
2349 ret = submit_extent_page(write_flags, tree, page,
2350 sector, iosize, pg_offset,
2351 bdev, &epd->bio, max_nr,
2352 end_bio_extent_writepage,
2358 pg_offset += iosize;
2363 /* make sure the mapping tag for page dirty gets cleared */
2364 set_page_writeback(page);
2365 end_page_writeback(page);
2371 /* drop our reference on any cached states */
2372 free_extent_state(cached_state);
2377 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2378 * @mapping: address space structure to write
2379 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2380 * @writepage: function called for each page
2381 * @data: data passed to writepage function
2383 * If a page is already under I/O, write_cache_pages() skips it, even
2384 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2385 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2386 * and msync() need to guarantee that all the data which was dirty at the time
2387 * the call was made get new I/O started against them. If wbc->sync_mode is
2388 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2389 * existing IO to complete.
2391 static int extent_write_cache_pages(struct extent_io_tree *tree,
2392 struct address_space *mapping,
2393 struct writeback_control *wbc,
2394 writepage_t writepage, void *data,
2395 void (*flush_fn)(void *))
2399 struct pagevec pvec;
2402 pgoff_t end; /* Inclusive */
2404 int range_whole = 0;
2406 pagevec_init(&pvec, 0);
2407 if (wbc->range_cyclic) {
2408 index = mapping->writeback_index; /* Start from prev offset */
2411 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2412 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2413 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2418 while (!done && (index <= end) &&
2419 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
2420 PAGECACHE_TAG_DIRTY, min(end - index,
2421 (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
2425 for (i = 0; i < nr_pages; i++) {
2426 struct page *page = pvec.pages[i];
2429 * At this point we hold neither mapping->tree_lock nor
2430 * lock on the page itself: the page may be truncated or
2431 * invalidated (changing page->mapping to NULL), or even
2432 * swizzled back from swapper_space to tmpfs file
2435 if (tree->ops && tree->ops->write_cache_pages_lock_hook)
2436 tree->ops->write_cache_pages_lock_hook(page);
2440 if (unlikely(page->mapping != mapping)) {
2445 if (!wbc->range_cyclic && page->index > end) {
2451 if (wbc->sync_mode != WB_SYNC_NONE) {
2452 if (PageWriteback(page))
2454 wait_on_page_writeback(page);
2457 if (PageWriteback(page) ||
2458 !clear_page_dirty_for_io(page)) {
2463 ret = (*writepage)(page, wbc, data);
2465 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
2469 if (ret || wbc->nr_to_write <= 0)
2472 pagevec_release(&pvec);
2475 if (!scanned && !done) {
2477 * We hit the last page and there is more work to be done: wrap
2478 * back to the start of the file
2487 static void flush_epd_write_bio(struct extent_page_data *epd)
2491 submit_one_bio(WRITE_SYNC, epd->bio, 0, 0);
2493 submit_one_bio(WRITE, epd->bio, 0, 0);
2498 static noinline void flush_write_bio(void *data)
2500 struct extent_page_data *epd = data;
2501 flush_epd_write_bio(epd);
2504 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
2505 get_extent_t *get_extent,
2506 struct writeback_control *wbc)
2509 struct address_space *mapping = page->mapping;
2510 struct extent_page_data epd = {
2513 .get_extent = get_extent,
2515 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
2517 struct writeback_control wbc_writepages = {
2519 .sync_mode = wbc->sync_mode,
2520 .older_than_this = NULL,
2522 .range_start = page_offset(page) + PAGE_CACHE_SIZE,
2523 .range_end = (loff_t)-1,
2526 ret = __extent_writepage(page, wbc, &epd);
2528 extent_write_cache_pages(tree, mapping, &wbc_writepages,
2529 __extent_writepage, &epd, flush_write_bio);
2530 flush_epd_write_bio(&epd);
2534 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
2535 u64 start, u64 end, get_extent_t *get_extent,
2539 struct address_space *mapping = inode->i_mapping;
2541 unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
2544 struct extent_page_data epd = {
2547 .get_extent = get_extent,
2549 .sync_io = mode == WB_SYNC_ALL,
2551 struct writeback_control wbc_writepages = {
2552 .bdi = inode->i_mapping->backing_dev_info,
2554 .older_than_this = NULL,
2555 .nr_to_write = nr_pages * 2,
2556 .range_start = start,
2557 .range_end = end + 1,
2560 while (start <= end) {
2561 page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
2562 if (clear_page_dirty_for_io(page))
2563 ret = __extent_writepage(page, &wbc_writepages, &epd);
2565 if (tree->ops && tree->ops->writepage_end_io_hook)
2566 tree->ops->writepage_end_io_hook(page, start,
2567 start + PAGE_CACHE_SIZE - 1,
2571 page_cache_release(page);
2572 start += PAGE_CACHE_SIZE;
2575 flush_epd_write_bio(&epd);
2579 int extent_writepages(struct extent_io_tree *tree,
2580 struct address_space *mapping,
2581 get_extent_t *get_extent,
2582 struct writeback_control *wbc)
2585 struct extent_page_data epd = {
2588 .get_extent = get_extent,
2590 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
2593 ret = extent_write_cache_pages(tree, mapping, wbc,
2594 __extent_writepage, &epd,
2596 flush_epd_write_bio(&epd);
2600 int extent_readpages(struct extent_io_tree *tree,
2601 struct address_space *mapping,
2602 struct list_head *pages, unsigned nr_pages,
2603 get_extent_t get_extent)
2605 struct bio *bio = NULL;
2607 struct pagevec pvec;
2608 unsigned long bio_flags = 0;
2610 pagevec_init(&pvec, 0);
2611 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
2612 struct page *page = list_entry(pages->prev, struct page, lru);
2614 prefetchw(&page->flags);
2615 list_del(&page->lru);
2617 * what we want to do here is call add_to_page_cache_lru,
2618 * but that isn't exported, so we reproduce it here
2620 if (!add_to_page_cache(page, mapping,
2621 page->index, GFP_KERNEL)) {
2623 /* open coding of lru_cache_add, also not exported */
2624 page_cache_get(page);
2625 if (!pagevec_add(&pvec, page))
2626 __pagevec_lru_add_file(&pvec);
2627 __extent_read_full_page(tree, page, get_extent,
2628 &bio, 0, &bio_flags);
2630 page_cache_release(page);
2632 if (pagevec_count(&pvec))
2633 __pagevec_lru_add_file(&pvec);
2634 BUG_ON(!list_empty(pages));
2636 submit_one_bio(READ, bio, 0, bio_flags);
2641 * basic invalidatepage code, this waits on any locked or writeback
2642 * ranges corresponding to the page, and then deletes any extent state
2643 * records from the tree
2645 int extent_invalidatepage(struct extent_io_tree *tree,
2646 struct page *page, unsigned long offset)
2648 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
2649 u64 end = start + PAGE_CACHE_SIZE - 1;
2650 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
2652 start += (offset + blocksize - 1) & ~(blocksize - 1);
2656 lock_extent(tree, start, end, GFP_NOFS);
2657 wait_on_page_writeback(page);
2658 clear_extent_bit(tree, start, end,
2659 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC,
2660 1, 1, NULL, GFP_NOFS);
2665 * simple commit_write call, set_range_dirty is used to mark both
2666 * the pages and the extent records as dirty
2668 int extent_commit_write(struct extent_io_tree *tree,
2669 struct inode *inode, struct page *page,
2670 unsigned from, unsigned to)
2672 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
2674 set_page_extent_mapped(page);
2675 set_page_dirty(page);
2677 if (pos > inode->i_size) {
2678 i_size_write(inode, pos);
2679 mark_inode_dirty(inode);
2684 int extent_prepare_write(struct extent_io_tree *tree,
2685 struct inode *inode, struct page *page,
2686 unsigned from, unsigned to, get_extent_t *get_extent)
2688 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2689 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
2691 u64 orig_block_start;
2694 struct extent_map *em;
2695 unsigned blocksize = 1 << inode->i_blkbits;
2696 size_t page_offset = 0;
2697 size_t block_off_start;
2698 size_t block_off_end;
2704 set_page_extent_mapped(page);
2706 block_start = (page_start + from) & ~((u64)blocksize - 1);
2707 block_end = (page_start + to - 1) | (blocksize - 1);
2708 orig_block_start = block_start;
2710 lock_extent(tree, page_start, page_end, GFP_NOFS);
2711 while (block_start <= block_end) {
2712 em = get_extent(inode, page, page_offset, block_start,
2713 block_end - block_start + 1, 1);
2714 if (IS_ERR(em) || !em)
2717 cur_end = min(block_end, extent_map_end(em) - 1);
2718 block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
2719 block_off_end = block_off_start + blocksize;
2720 isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);
2722 if (!PageUptodate(page) && isnew &&
2723 (block_off_end > to || block_off_start < from)) {
2726 kaddr = kmap_atomic(page, KM_USER0);
2727 if (block_off_end > to)
2728 memset(kaddr + to, 0, block_off_end - to);
2729 if (block_off_start < from)
2730 memset(kaddr + block_off_start, 0,
2731 from - block_off_start);
2732 flush_dcache_page(page);
2733 kunmap_atomic(kaddr, KM_USER0);
2735 if ((em->block_start != EXTENT_MAP_HOLE &&
2736 em->block_start != EXTENT_MAP_INLINE) &&
2737 !isnew && !PageUptodate(page) &&
2738 (block_off_end > to || block_off_start < from) &&
2739 !test_range_bit(tree, block_start, cur_end,
2740 EXTENT_UPTODATE, 1, NULL)) {
2742 u64 extent_offset = block_start - em->start;
2744 sector = (em->block_start + extent_offset) >> 9;
2745 iosize = (cur_end - block_start + blocksize) &
2746 ~((u64)blocksize - 1);
2748 * we've already got the extent locked, but we
2749 * need to split the state such that our end_bio
2750 * handler can clear the lock.
2752 set_extent_bit(tree, block_start,
2753 block_start + iosize - 1,
2754 EXTENT_LOCKED, 0, NULL, NULL, GFP_NOFS);
2755 ret = submit_extent_page(READ, tree, page,
2756 sector, iosize, page_offset, em->bdev,
2758 end_bio_extent_preparewrite, 0,
2761 block_start = block_start + iosize;
2763 set_extent_uptodate(tree, block_start, cur_end,
2765 unlock_extent(tree, block_start, cur_end, GFP_NOFS);
2766 block_start = cur_end + 1;
2768 page_offset = block_start & (PAGE_CACHE_SIZE - 1);
2769 free_extent_map(em);
2772 wait_extent_bit(tree, orig_block_start,
2773 block_end, EXTENT_LOCKED);
2775 check_page_uptodate(tree, page);
2777 /* FIXME, zero out newly allocated blocks on error */
2782 * a helper for releasepage, this tests for areas of the page that
2783 * are locked or under IO and drops the related state bits if it is safe
2786 int try_release_extent_state(struct extent_map_tree *map,
2787 struct extent_io_tree *tree, struct page *page,
2790 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2791 u64 end = start + PAGE_CACHE_SIZE - 1;
2794 if (test_range_bit(tree, start, end,
2795 EXTENT_IOBITS | EXTENT_ORDERED, 0, NULL))
2798 if ((mask & GFP_NOFS) == GFP_NOFS)
2800 clear_extent_bit(tree, start, end, EXTENT_UPTODATE,
2807 * a helper for releasepage. As long as there are no locked extents
2808 * in the range corresponding to the page, both state records and extent
2809 * map records are removed
2811 int try_release_extent_mapping(struct extent_map_tree *map,
2812 struct extent_io_tree *tree, struct page *page,
2815 struct extent_map *em;
2816 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2817 u64 end = start + PAGE_CACHE_SIZE - 1;
2819 if ((mask & __GFP_WAIT) &&
2820 page->mapping->host->i_size > 16 * 1024 * 1024) {
2822 while (start <= end) {
2823 len = end - start + 1;
2824 write_lock(&map->lock);
2825 em = lookup_extent_mapping(map, start, len);
2826 if (!em || IS_ERR(em)) {
2827 write_unlock(&map->lock);
2830 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
2831 em->start != start) {
2832 write_unlock(&map->lock);
2833 free_extent_map(em);
2836 if (!test_range_bit(tree, em->start,
2837 extent_map_end(em) - 1,
2838 EXTENT_LOCKED | EXTENT_WRITEBACK |
2841 remove_extent_mapping(map, em);
2842 /* once for the rb tree */
2843 free_extent_map(em);
2845 start = extent_map_end(em);
2846 write_unlock(&map->lock);
2849 free_extent_map(em);
2852 return try_release_extent_state(map, tree, page, mask);
2855 sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
2856 get_extent_t *get_extent)
2858 struct inode *inode = mapping->host;
2859 u64 start = iblock << inode->i_blkbits;
2860 sector_t sector = 0;
2861 size_t blksize = (1 << inode->i_blkbits);
2862 struct extent_map *em;
2864 lock_extent(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
2866 em = get_extent(inode, NULL, 0, start, blksize, 0);
2867 unlock_extent(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
2869 if (!em || IS_ERR(em))
2872 if (em->block_start > EXTENT_MAP_LAST_BYTE)
2875 sector = (em->block_start + start - em->start) >> inode->i_blkbits;
2877 free_extent_map(em);
2881 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2882 __u64 start, __u64 len, get_extent_t *get_extent)
2886 u64 max = start + len;
2889 struct extent_map *em = NULL;
2891 u64 em_start = 0, em_len = 0;
2892 unsigned long emflags;
2898 lock_extent(&BTRFS_I(inode)->io_tree, start, start + len,
2900 em = get_extent(inode, NULL, 0, off, max - off, 0);
2908 off = em->start + em->len;
2912 em_start = em->start;
2918 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
2920 flags |= FIEMAP_EXTENT_LAST;
2921 } else if (em->block_start == EXTENT_MAP_HOLE) {
2922 flags |= FIEMAP_EXTENT_UNWRITTEN;
2923 } else if (em->block_start == EXTENT_MAP_INLINE) {
2924 flags |= (FIEMAP_EXTENT_DATA_INLINE |
2925 FIEMAP_EXTENT_NOT_ALIGNED);
2926 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
2927 flags |= (FIEMAP_EXTENT_DELALLOC |
2928 FIEMAP_EXTENT_UNKNOWN);
2930 disko = em->block_start;
2932 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
2933 flags |= FIEMAP_EXTENT_ENCODED;
2935 emflags = em->flags;
2936 free_extent_map(em);
2940 em = get_extent(inode, NULL, 0, off, max - off, 0);
2947 emflags = em->flags;
2949 if (test_bit(EXTENT_FLAG_VACANCY, &emflags)) {
2950 flags |= FIEMAP_EXTENT_LAST;
2954 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
2960 free_extent_map(em);
2962 unlock_extent(&BTRFS_I(inode)->io_tree, start, start + len,
2967 static inline struct page *extent_buffer_page(struct extent_buffer *eb,
2971 struct address_space *mapping;
2974 return eb->first_page;
2975 i += eb->start >> PAGE_CACHE_SHIFT;
2976 mapping = eb->first_page->mapping;
2981 * extent_buffer_page is only called after pinning the page
2982 * by increasing the reference count. So we know the page must
2983 * be in the radix tree.
2986 p = radix_tree_lookup(&mapping->page_tree, i);
2992 static inline unsigned long num_extent_pages(u64 start, u64 len)
2994 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
2995 (start >> PAGE_CACHE_SHIFT);
2998 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
3003 struct extent_buffer *eb = NULL;
3005 unsigned long flags;
3008 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
3011 spin_lock_init(&eb->lock);
3012 init_waitqueue_head(&eb->lock_wq);
3015 spin_lock_irqsave(&leak_lock, flags);
3016 list_add(&eb->leak_list, &buffers);
3017 spin_unlock_irqrestore(&leak_lock, flags);
3019 atomic_set(&eb->refs, 1);
3024 static void __free_extent_buffer(struct extent_buffer *eb)
3027 unsigned long flags;
3028 spin_lock_irqsave(&leak_lock, flags);
3029 list_del(&eb->leak_list);
3030 spin_unlock_irqrestore(&leak_lock, flags);
3032 kmem_cache_free(extent_buffer_cache, eb);
3035 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
3036 u64 start, unsigned long len,
3040 unsigned long num_pages = num_extent_pages(start, len);
3042 unsigned long index = start >> PAGE_CACHE_SHIFT;
3043 struct extent_buffer *eb;
3044 struct extent_buffer *exists = NULL;
3046 struct address_space *mapping = tree->mapping;
3049 spin_lock(&tree->buffer_lock);
3050 eb = buffer_search(tree, start);
3052 atomic_inc(&eb->refs);
3053 spin_unlock(&tree->buffer_lock);
3054 mark_page_accessed(eb->first_page);
3057 spin_unlock(&tree->buffer_lock);
3059 eb = __alloc_extent_buffer(tree, start, len, mask);
3064 eb->first_page = page0;
3067 page_cache_get(page0);
3068 mark_page_accessed(page0);
3069 set_page_extent_mapped(page0);
3070 set_page_extent_head(page0, len);
3071 uptodate = PageUptodate(page0);
3075 for (; i < num_pages; i++, index++) {
3076 p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
3081 set_page_extent_mapped(p);
3082 mark_page_accessed(p);
3085 set_page_extent_head(p, len);
3087 set_page_private(p, EXTENT_PAGE_PRIVATE);
3089 if (!PageUptodate(p))
3094 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3096 spin_lock(&tree->buffer_lock);
3097 exists = buffer_tree_insert(tree, start, &eb->rb_node);
3099 /* add one reference for the caller */
3100 atomic_inc(&exists->refs);
3101 spin_unlock(&tree->buffer_lock);
3104 spin_unlock(&tree->buffer_lock);
3106 /* add one reference for the tree */
3107 atomic_inc(&eb->refs);
3111 if (!atomic_dec_and_test(&eb->refs))
3113 for (index = 1; index < i; index++)
3114 page_cache_release(extent_buffer_page(eb, index));
3115 page_cache_release(extent_buffer_page(eb, 0));
3116 __free_extent_buffer(eb);
3120 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
3121 u64 start, unsigned long len,
3124 struct extent_buffer *eb;
3126 spin_lock(&tree->buffer_lock);
3127 eb = buffer_search(tree, start);
3129 atomic_inc(&eb->refs);
3130 spin_unlock(&tree->buffer_lock);
3133 mark_page_accessed(eb->first_page);
3138 void free_extent_buffer(struct extent_buffer *eb)
3143 if (!atomic_dec_and_test(&eb->refs))
3149 int clear_extent_buffer_dirty(struct extent_io_tree *tree,
3150 struct extent_buffer *eb)
3153 unsigned long num_pages;
3156 num_pages = num_extent_pages(eb->start, eb->len);
3158 for (i = 0; i < num_pages; i++) {
3159 page = extent_buffer_page(eb, i);
3160 if (!PageDirty(page))
3165 set_page_extent_head(page, eb->len);
3167 set_page_private(page, EXTENT_PAGE_PRIVATE);
3169 clear_page_dirty_for_io(page);
3170 spin_lock_irq(&page->mapping->tree_lock);
3171 if (!PageDirty(page)) {
3172 radix_tree_tag_clear(&page->mapping->page_tree,
3174 PAGECACHE_TAG_DIRTY);
3176 spin_unlock_irq(&page->mapping->tree_lock);
3182 int wait_on_extent_buffer_writeback(struct extent_io_tree *tree,
3183 struct extent_buffer *eb)
3185 return wait_on_extent_writeback(tree, eb->start,
3186 eb->start + eb->len - 1);
3189 int set_extent_buffer_dirty(struct extent_io_tree *tree,
3190 struct extent_buffer *eb)
3193 unsigned long num_pages;
3196 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
3197 num_pages = num_extent_pages(eb->start, eb->len);
3198 for (i = 0; i < num_pages; i++)
3199 __set_page_dirty_nobuffers(extent_buffer_page(eb, i));
3203 int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
3204 struct extent_buffer *eb)
3208 unsigned long num_pages;
3210 num_pages = num_extent_pages(eb->start, eb->len);
3211 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3213 clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3215 for (i = 0; i < num_pages; i++) {
3216 page = extent_buffer_page(eb, i);
3218 ClearPageUptodate(page);
3223 int set_extent_buffer_uptodate(struct extent_io_tree *tree,
3224 struct extent_buffer *eb)
3228 unsigned long num_pages;
3230 num_pages = num_extent_pages(eb->start, eb->len);
3232 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3234 for (i = 0; i < num_pages; i++) {
3235 page = extent_buffer_page(eb, i);
3236 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
3237 ((i == num_pages - 1) &&
3238 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
3239 check_page_uptodate(tree, page);
3242 SetPageUptodate(page);
3247 int extent_range_uptodate(struct extent_io_tree *tree,
3252 int pg_uptodate = 1;
3254 unsigned long index;
3256 ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL);
3259 while (start <= end) {
3260 index = start >> PAGE_CACHE_SHIFT;
3261 page = find_get_page(tree->mapping, index);
3262 uptodate = PageUptodate(page);
3263 page_cache_release(page);
3268 start += PAGE_CACHE_SIZE;
3273 int extent_buffer_uptodate(struct extent_io_tree *tree,
3274 struct extent_buffer *eb)
3277 unsigned long num_pages;
3280 int pg_uptodate = 1;
3282 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3285 ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3286 EXTENT_UPTODATE, 1, NULL);
3290 num_pages = num_extent_pages(eb->start, eb->len);
3291 for (i = 0; i < num_pages; i++) {
3292 page = extent_buffer_page(eb, i);
3293 if (!PageUptodate(page)) {
3301 int read_extent_buffer_pages(struct extent_io_tree *tree,
3302 struct extent_buffer *eb,
3303 u64 start, int wait,
3304 get_extent_t *get_extent, int mirror_num)
3307 unsigned long start_i;
3311 int locked_pages = 0;
3312 int all_uptodate = 1;
3313 int inc_all_pages = 0;
3314 unsigned long num_pages;
3315 struct bio *bio = NULL;
3316 unsigned long bio_flags = 0;
3318 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3321 if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3322 EXTENT_UPTODATE, 1, NULL)) {
3327 WARN_ON(start < eb->start);
3328 start_i = (start >> PAGE_CACHE_SHIFT) -
3329 (eb->start >> PAGE_CACHE_SHIFT);
3334 num_pages = num_extent_pages(eb->start, eb->len);
3335 for (i = start_i; i < num_pages; i++) {
3336 page = extent_buffer_page(eb, i);
3338 if (!trylock_page(page))
3344 if (!PageUptodate(page))
3349 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3353 for (i = start_i; i < num_pages; i++) {
3354 page = extent_buffer_page(eb, i);
3356 page_cache_get(page);
3357 if (!PageUptodate(page)) {
3360 ClearPageError(page);
3361 err = __extent_read_full_page(tree, page,
3363 mirror_num, &bio_flags);
3372 submit_one_bio(READ, bio, mirror_num, bio_flags);
3377 for (i = start_i; i < num_pages; i++) {
3378 page = extent_buffer_page(eb, i);
3379 wait_on_page_locked(page);
3380 if (!PageUptodate(page))
3385 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3390 while (locked_pages > 0) {
3391 page = extent_buffer_page(eb, i);
3399 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
3400 unsigned long start,
3407 char *dst = (char *)dstv;
3408 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3409 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3411 WARN_ON(start > eb->len);
3412 WARN_ON(start + len > eb->start + eb->len);
3414 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3417 page = extent_buffer_page(eb, i);
3419 cur = min(len, (PAGE_CACHE_SIZE - offset));
3420 kaddr = kmap_atomic(page, KM_USER1);
3421 memcpy(dst, kaddr + offset, cur);
3422 kunmap_atomic(kaddr, KM_USER1);
3431 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
3432 unsigned long min_len, char **token, char **map,
3433 unsigned long *map_start,
3434 unsigned long *map_len, int km)
3436 size_t offset = start & (PAGE_CACHE_SIZE - 1);
3439 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3440 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3441 unsigned long end_i = (start_offset + start + min_len - 1) >>
3448 offset = start_offset;
3452 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
3455 if (start + min_len > eb->len) {
3456 printk(KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
3457 "wanted %lu %lu\n", (unsigned long long)eb->start,
3458 eb->len, start, min_len);
3462 p = extent_buffer_page(eb, i);
3463 kaddr = kmap_atomic(p, km);
3465 *map = kaddr + offset;
3466 *map_len = PAGE_CACHE_SIZE - offset;
3470 int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
3471 unsigned long min_len,
3472 char **token, char **map,
3473 unsigned long *map_start,
3474 unsigned long *map_len, int km)
3478 if (eb->map_token) {
3479 unmap_extent_buffer(eb, eb->map_token, km);
3480 eb->map_token = NULL;
3483 err = map_private_extent_buffer(eb, start, min_len, token, map,
3484 map_start, map_len, km);
3486 eb->map_token = *token;
3488 eb->map_start = *map_start;
3489 eb->map_len = *map_len;
3494 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)
3496 kunmap_atomic(token, km);
3499 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
3500 unsigned long start,
3507 char *ptr = (char *)ptrv;
3508 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3509 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3512 WARN_ON(start > eb->len);
3513 WARN_ON(start + len > eb->start + eb->len);
3515 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3518 page = extent_buffer_page(eb, i);
3520 cur = min(len, (PAGE_CACHE_SIZE - offset));
3522 kaddr = kmap_atomic(page, KM_USER0);
3523 ret = memcmp(ptr, kaddr + offset, cur);
3524 kunmap_atomic(kaddr, KM_USER0);
3536 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
3537 unsigned long start, unsigned long len)
3543 char *src = (char *)srcv;
3544 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3545 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3547 WARN_ON(start > eb->len);
3548 WARN_ON(start + len > eb->start + eb->len);
3550 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3553 page = extent_buffer_page(eb, i);
3554 WARN_ON(!PageUptodate(page));
3556 cur = min(len, PAGE_CACHE_SIZE - offset);
3557 kaddr = kmap_atomic(page, KM_USER1);
3558 memcpy(kaddr + offset, src, cur);
3559 kunmap_atomic(kaddr, KM_USER1);
3568 void memset_extent_buffer(struct extent_buffer *eb, char c,
3569 unsigned long start, unsigned long len)
3575 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3576 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3578 WARN_ON(start > eb->len);
3579 WARN_ON(start + len > eb->start + eb->len);
3581 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3584 page = extent_buffer_page(eb, i);
3585 WARN_ON(!PageUptodate(page));
3587 cur = min(len, PAGE_CACHE_SIZE - offset);
3588 kaddr = kmap_atomic(page, KM_USER0);
3589 memset(kaddr + offset, c, cur);
3590 kunmap_atomic(kaddr, KM_USER0);
3598 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
3599 unsigned long dst_offset, unsigned long src_offset,
3602 u64 dst_len = dst->len;
3607 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3608 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3610 WARN_ON(src->len != dst_len);
3612 offset = (start_offset + dst_offset) &
3613 ((unsigned long)PAGE_CACHE_SIZE - 1);
3616 page = extent_buffer_page(dst, i);
3617 WARN_ON(!PageUptodate(page));
3619 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
3621 kaddr = kmap_atomic(page, KM_USER0);
3622 read_extent_buffer(src, kaddr + offset, src_offset, cur);
3623 kunmap_atomic(kaddr, KM_USER0);
3632 static void move_pages(struct page *dst_page, struct page *src_page,
3633 unsigned long dst_off, unsigned long src_off,
3636 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3637 if (dst_page == src_page) {
3638 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
3640 char *src_kaddr = kmap_atomic(src_page, KM_USER1);
3641 char *p = dst_kaddr + dst_off + len;
3642 char *s = src_kaddr + src_off + len;
3647 kunmap_atomic(src_kaddr, KM_USER1);
3649 kunmap_atomic(dst_kaddr, KM_USER0);
3652 static void copy_pages(struct page *dst_page, struct page *src_page,
3653 unsigned long dst_off, unsigned long src_off,
3656 char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
3659 if (dst_page != src_page)
3660 src_kaddr = kmap_atomic(src_page, KM_USER1);
3662 src_kaddr = dst_kaddr;
3664 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
3665 kunmap_atomic(dst_kaddr, KM_USER0);
3666 if (dst_page != src_page)
3667 kunmap_atomic(src_kaddr, KM_USER1);
3670 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3671 unsigned long src_offset, unsigned long len)
3674 size_t dst_off_in_page;
3675 size_t src_off_in_page;
3676 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3677 unsigned long dst_i;
3678 unsigned long src_i;
3680 if (src_offset + len > dst->len) {
3681 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
3682 "len %lu dst len %lu\n", src_offset, len, dst->len);
3685 if (dst_offset + len > dst->len) {
3686 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
3687 "len %lu dst len %lu\n", dst_offset, len, dst->len);
3692 dst_off_in_page = (start_offset + dst_offset) &
3693 ((unsigned long)PAGE_CACHE_SIZE - 1);
3694 src_off_in_page = (start_offset + src_offset) &
3695 ((unsigned long)PAGE_CACHE_SIZE - 1);
3697 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
3698 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
3700 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
3702 cur = min_t(unsigned long, cur,
3703 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
3705 copy_pages(extent_buffer_page(dst, dst_i),
3706 extent_buffer_page(dst, src_i),
3707 dst_off_in_page, src_off_in_page, cur);
3715 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
3716 unsigned long src_offset, unsigned long len)
3719 size_t dst_off_in_page;
3720 size_t src_off_in_page;
3721 unsigned long dst_end = dst_offset + len - 1;
3722 unsigned long src_end = src_offset + len - 1;
3723 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
3724 unsigned long dst_i;
3725 unsigned long src_i;
3727 if (src_offset + len > dst->len) {
3728 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
3729 "len %lu len %lu\n", src_offset, len, dst->len);
3732 if (dst_offset + len > dst->len) {
3733 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
3734 "len %lu len %lu\n", dst_offset, len, dst->len);
3737 if (dst_offset < src_offset) {
3738 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
3742 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
3743 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
3745 dst_off_in_page = (start_offset + dst_end) &
3746 ((unsigned long)PAGE_CACHE_SIZE - 1);
3747 src_off_in_page = (start_offset + src_end) &
3748 ((unsigned long)PAGE_CACHE_SIZE - 1);
3750 cur = min_t(unsigned long, len, src_off_in_page + 1);
3751 cur = min(cur, dst_off_in_page + 1);
3752 move_pages(extent_buffer_page(dst, dst_i),
3753 extent_buffer_page(dst, src_i),
3754 dst_off_in_page - cur + 1,
3755 src_off_in_page - cur + 1, cur);
3763 int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
3765 u64 start = page_offset(page);
3766 struct extent_buffer *eb;
3769 unsigned long num_pages;
3771 spin_lock(&tree->buffer_lock);
3772 eb = buffer_search(tree, start);
3776 if (atomic_read(&eb->refs) > 1) {
3780 if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3784 /* at this point we can safely release the extent buffer */
3785 num_pages = num_extent_pages(eb->start, eb->len);
3786 for (i = 0; i < num_pages; i++)
3787 page_cache_release(extent_buffer_page(eb, i));
3788 rb_erase(&eb->rb_node, &tree->buffer);
3789 __free_extent_buffer(eb);
3791 spin_unlock(&tree->buffer_lock);