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"
22 static struct kmem_cache *extent_state_cache;
23 static struct kmem_cache *extent_buffer_cache;
25 static LIST_HEAD(buffers);
26 static LIST_HEAD(states);
30 static DEFINE_SPINLOCK(leak_lock);
33 #define BUFFER_LRU_MAX 64
38 struct rb_node rb_node;
41 struct extent_page_data {
43 struct extent_io_tree *tree;
44 get_extent_t *get_extent;
46 /* tells writepage not to lock the state bits for this range
47 * it still does the unlocking
49 unsigned int extent_locked:1;
51 /* tells the submit_bio code to use a WRITE_SYNC */
52 unsigned int sync_io:1;
55 int __init extent_io_init(void)
57 extent_state_cache = kmem_cache_create("extent_state",
58 sizeof(struct extent_state), 0,
59 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
60 if (!extent_state_cache)
63 extent_buffer_cache = kmem_cache_create("extent_buffers",
64 sizeof(struct extent_buffer), 0,
65 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
66 if (!extent_buffer_cache)
67 goto free_state_cache;
71 kmem_cache_destroy(extent_state_cache);
75 void extent_io_exit(void)
77 struct extent_state *state;
78 struct extent_buffer *eb;
80 while (!list_empty(&states)) {
81 state = list_entry(states.next, struct extent_state, leak_list);
82 printk(KERN_ERR "btrfs state leak: start %llu end %llu "
83 "state %lu in tree %p refs %d\n",
84 (unsigned long long)state->start,
85 (unsigned long long)state->end,
86 state->state, state->tree, atomic_read(&state->refs));
87 list_del(&state->leak_list);
88 kmem_cache_free(extent_state_cache, state);
92 while (!list_empty(&buffers)) {
93 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
94 printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
95 "refs %d\n", (unsigned long long)eb->start,
96 eb->len, atomic_read(&eb->refs));
97 list_del(&eb->leak_list);
98 kmem_cache_free(extent_buffer_cache, eb);
100 if (extent_state_cache)
101 kmem_cache_destroy(extent_state_cache);
102 if (extent_buffer_cache)
103 kmem_cache_destroy(extent_buffer_cache);
106 void extent_io_tree_init(struct extent_io_tree *tree,
107 struct address_space *mapping)
109 tree->state = RB_ROOT;
110 INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
112 tree->dirty_bytes = 0;
113 spin_lock_init(&tree->lock);
114 spin_lock_init(&tree->buffer_lock);
115 tree->mapping = mapping;
118 static struct extent_state *alloc_extent_state(gfp_t mask)
120 struct extent_state *state;
125 state = kmem_cache_alloc(extent_state_cache, mask);
132 spin_lock_irqsave(&leak_lock, flags);
133 list_add(&state->leak_list, &states);
134 spin_unlock_irqrestore(&leak_lock, flags);
136 atomic_set(&state->refs, 1);
137 init_waitqueue_head(&state->wq);
141 void free_extent_state(struct extent_state *state)
145 if (atomic_dec_and_test(&state->refs)) {
149 WARN_ON(state->tree);
151 spin_lock_irqsave(&leak_lock, flags);
152 list_del(&state->leak_list);
153 spin_unlock_irqrestore(&leak_lock, flags);
155 kmem_cache_free(extent_state_cache, state);
159 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
160 struct rb_node *node)
162 struct rb_node **p = &root->rb_node;
163 struct rb_node *parent = NULL;
164 struct tree_entry *entry;
168 entry = rb_entry(parent, struct tree_entry, rb_node);
170 if (offset < entry->start)
172 else if (offset > entry->end)
178 entry = rb_entry(node, struct tree_entry, rb_node);
179 rb_link_node(node, parent, p);
180 rb_insert_color(node, root);
184 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
185 struct rb_node **prev_ret,
186 struct rb_node **next_ret)
188 struct rb_root *root = &tree->state;
189 struct rb_node *n = root->rb_node;
190 struct rb_node *prev = NULL;
191 struct rb_node *orig_prev = NULL;
192 struct tree_entry *entry;
193 struct tree_entry *prev_entry = NULL;
196 entry = rb_entry(n, struct tree_entry, rb_node);
200 if (offset < entry->start)
202 else if (offset > entry->end)
210 while (prev && offset > prev_entry->end) {
211 prev = rb_next(prev);
212 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
219 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
220 while (prev && offset < prev_entry->start) {
221 prev = rb_prev(prev);
222 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
229 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
232 struct rb_node *prev = NULL;
235 ret = __etree_search(tree, offset, &prev, NULL);
241 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
242 struct extent_state *other)
244 if (tree->ops && tree->ops->merge_extent_hook)
245 tree->ops->merge_extent_hook(tree->mapping->host, new,
250 * utility function to look for merge candidates inside a given range.
251 * Any extents with matching state are merged together into a single
252 * extent in the tree. Extents with EXTENT_IO in their state field
253 * are not merged because the end_io handlers need to be able to do
254 * operations on them without sleeping (or doing allocations/splits).
256 * This should be called with the tree lock held.
258 static void merge_state(struct extent_io_tree *tree,
259 struct extent_state *state)
261 struct extent_state *other;
262 struct rb_node *other_node;
264 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
267 other_node = rb_prev(&state->rb_node);
269 other = rb_entry(other_node, struct extent_state, rb_node);
270 if (other->end == state->start - 1 &&
271 other->state == state->state) {
272 merge_cb(tree, state, other);
273 state->start = other->start;
275 rb_erase(&other->rb_node, &tree->state);
276 free_extent_state(other);
279 other_node = rb_next(&state->rb_node);
281 other = rb_entry(other_node, struct extent_state, rb_node);
282 if (other->start == state->end + 1 &&
283 other->state == state->state) {
284 merge_cb(tree, state, other);
285 state->end = other->end;
287 rb_erase(&other->rb_node, &tree->state);
288 free_extent_state(other);
293 static void set_state_cb(struct extent_io_tree *tree,
294 struct extent_state *state, int *bits)
296 if (tree->ops && tree->ops->set_bit_hook)
297 tree->ops->set_bit_hook(tree->mapping->host, state, bits);
300 static void clear_state_cb(struct extent_io_tree *tree,
301 struct extent_state *state, int *bits)
303 if (tree->ops && tree->ops->clear_bit_hook)
304 tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
307 static void set_state_bits(struct extent_io_tree *tree,
308 struct extent_state *state, int *bits);
311 * insert an extent_state struct into the tree. 'bits' are set on the
312 * struct before it is inserted.
314 * This may return -EEXIST if the extent is already there, in which case the
315 * state struct is freed.
317 * The tree lock is not taken internally. This is a utility function and
318 * probably isn't what you want to call (see set/clear_extent_bit).
320 static int insert_state(struct extent_io_tree *tree,
321 struct extent_state *state, u64 start, u64 end,
324 struct rb_node *node;
327 printk(KERN_ERR "btrfs end < start %llu %llu\n",
328 (unsigned long long)end,
329 (unsigned long long)start);
332 state->start = start;
335 set_state_bits(tree, state, bits);
337 node = tree_insert(&tree->state, end, &state->rb_node);
339 struct extent_state *found;
340 found = rb_entry(node, struct extent_state, rb_node);
341 printk(KERN_ERR "btrfs found node %llu %llu on insert of "
342 "%llu %llu\n", (unsigned long long)found->start,
343 (unsigned long long)found->end,
344 (unsigned long long)start, (unsigned long long)end);
348 merge_state(tree, state);
352 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
355 if (tree->ops && tree->ops->split_extent_hook)
356 tree->ops->split_extent_hook(tree->mapping->host, orig, split);
360 * split a given extent state struct in two, inserting the preallocated
361 * struct 'prealloc' as the newly created second half. 'split' indicates an
362 * offset inside 'orig' where it should be split.
365 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
366 * are two extent state structs in the tree:
367 * prealloc: [orig->start, split - 1]
368 * orig: [ split, orig->end ]
370 * The tree locks are not taken by this function. They need to be held
373 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
374 struct extent_state *prealloc, u64 split)
376 struct rb_node *node;
378 split_cb(tree, orig, split);
380 prealloc->start = orig->start;
381 prealloc->end = split - 1;
382 prealloc->state = orig->state;
385 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
387 free_extent_state(prealloc);
390 prealloc->tree = tree;
395 * utility function to clear some bits in an extent state struct.
396 * it will optionally wake up any one waiting on this state (wake == 1), or
397 * forcibly remove the state from the tree (delete == 1).
399 * If no bits are set on the state struct after clearing things, the
400 * struct is freed and removed from the tree
402 static int clear_state_bit(struct extent_io_tree *tree,
403 struct extent_state *state,
406 int bits_to_clear = *bits & ~EXTENT_CTLBITS;
407 int ret = state->state & bits_to_clear;
409 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
410 u64 range = state->end - state->start + 1;
411 WARN_ON(range > tree->dirty_bytes);
412 tree->dirty_bytes -= range;
414 clear_state_cb(tree, state, bits);
415 state->state &= ~bits_to_clear;
418 if (state->state == 0) {
420 rb_erase(&state->rb_node, &tree->state);
422 free_extent_state(state);
427 merge_state(tree, state);
432 static struct extent_state *
433 alloc_extent_state_atomic(struct extent_state *prealloc)
436 prealloc = alloc_extent_state(GFP_ATOMIC);
442 * clear some bits on a range in the tree. This may require splitting
443 * or inserting elements in the tree, so the gfp mask is used to
444 * indicate which allocations or sleeping are allowed.
446 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
447 * the given range from the tree regardless of state (ie for truncate).
449 * the range [start, end] is inclusive.
451 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
452 * bits were already set, or zero if none of the bits were already set.
454 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
455 int bits, int wake, int delete,
456 struct extent_state **cached_state,
459 struct extent_state *state;
460 struct extent_state *cached;
461 struct extent_state *prealloc = NULL;
462 struct rb_node *next_node;
463 struct rb_node *node;
470 bits |= ~EXTENT_CTLBITS;
471 bits |= EXTENT_FIRST_DELALLOC;
473 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
476 if (!prealloc && (mask & __GFP_WAIT)) {
477 prealloc = alloc_extent_state(mask);
482 spin_lock(&tree->lock);
484 cached = *cached_state;
487 *cached_state = NULL;
491 if (cached && cached->tree && cached->start <= start &&
492 cached->end > start) {
494 atomic_dec(&cached->refs);
499 free_extent_state(cached);
502 * this search will find the extents that end after
505 node = tree_search(tree, start);
508 state = rb_entry(node, struct extent_state, rb_node);
510 if (state->start > end)
512 WARN_ON(state->end < start);
513 last_end = state->end;
516 * | ---- desired range ---- |
518 * | ------------- state -------------- |
520 * We need to split the extent we found, and may flip
521 * bits on second half.
523 * If the extent we found extends past our range, we
524 * just split and search again. It'll get split again
525 * the next time though.
527 * If the extent we found is inside our range, we clear
528 * the desired bit on it.
531 if (state->start < start) {
532 prealloc = alloc_extent_state_atomic(prealloc);
534 err = split_state(tree, state, prealloc, start);
535 BUG_ON(err == -EEXIST);
539 if (state->end <= end) {
540 set |= clear_state_bit(tree, state, &bits, wake);
541 if (last_end == (u64)-1)
543 start = last_end + 1;
548 * | ---- desired range ---- |
550 * We need to split the extent, and clear the bit
553 if (state->start <= end && state->end > end) {
554 prealloc = alloc_extent_state_atomic(prealloc);
556 err = split_state(tree, state, prealloc, end + 1);
557 BUG_ON(err == -EEXIST);
561 set |= clear_state_bit(tree, prealloc, &bits, wake);
567 if (state->end < end && prealloc && !need_resched())
568 next_node = rb_next(&state->rb_node);
572 set |= clear_state_bit(tree, state, &bits, wake);
573 if (last_end == (u64)-1)
575 start = last_end + 1;
576 if (start <= end && next_node) {
577 state = rb_entry(next_node, struct extent_state,
579 if (state->start == start)
585 spin_unlock(&tree->lock);
587 free_extent_state(prealloc);
594 spin_unlock(&tree->lock);
595 if (mask & __GFP_WAIT)
600 static int wait_on_state(struct extent_io_tree *tree,
601 struct extent_state *state)
602 __releases(tree->lock)
603 __acquires(tree->lock)
606 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
607 spin_unlock(&tree->lock);
609 spin_lock(&tree->lock);
610 finish_wait(&state->wq, &wait);
615 * waits for one or more bits to clear on a range in the state tree.
616 * The range [start, end] is inclusive.
617 * The tree lock is taken by this function
619 int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
621 struct extent_state *state;
622 struct rb_node *node;
624 spin_lock(&tree->lock);
628 * this search will find all the extents that end after
631 node = tree_search(tree, start);
635 state = rb_entry(node, struct extent_state, rb_node);
637 if (state->start > end)
640 if (state->state & bits) {
641 start = state->start;
642 atomic_inc(&state->refs);
643 wait_on_state(tree, state);
644 free_extent_state(state);
647 start = state->end + 1;
652 cond_resched_lock(&tree->lock);
655 spin_unlock(&tree->lock);
659 static void set_state_bits(struct extent_io_tree *tree,
660 struct extent_state *state,
663 int bits_to_set = *bits & ~EXTENT_CTLBITS;
665 set_state_cb(tree, state, bits);
666 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
667 u64 range = state->end - state->start + 1;
668 tree->dirty_bytes += range;
670 state->state |= bits_to_set;
673 static void cache_state(struct extent_state *state,
674 struct extent_state **cached_ptr)
676 if (cached_ptr && !(*cached_ptr)) {
677 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
679 atomic_inc(&state->refs);
684 static void uncache_state(struct extent_state **cached_ptr)
686 if (cached_ptr && (*cached_ptr)) {
687 struct extent_state *state = *cached_ptr;
689 free_extent_state(state);
694 * set some bits on a range in the tree. This may require allocations or
695 * sleeping, so the gfp mask is used to indicate what is allowed.
697 * If any of the exclusive bits are set, this will fail with -EEXIST if some
698 * part of the range already has the desired bits set. The start of the
699 * existing range is returned in failed_start in this case.
701 * [start, end] is inclusive This takes the tree lock.
704 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
705 int bits, int exclusive_bits, u64 *failed_start,
706 struct extent_state **cached_state, gfp_t mask)
708 struct extent_state *state;
709 struct extent_state *prealloc = NULL;
710 struct rb_node *node;
715 bits |= EXTENT_FIRST_DELALLOC;
717 if (!prealloc && (mask & __GFP_WAIT)) {
718 prealloc = alloc_extent_state(mask);
722 spin_lock(&tree->lock);
723 if (cached_state && *cached_state) {
724 state = *cached_state;
725 if (state->start <= start && state->end > start &&
727 node = &state->rb_node;
732 * this search will find all the extents that end after
735 node = tree_search(tree, start);
737 prealloc = alloc_extent_state_atomic(prealloc);
739 err = insert_state(tree, prealloc, start, end, &bits);
741 BUG_ON(err == -EEXIST);
744 state = rb_entry(node, struct extent_state, rb_node);
746 last_start = state->start;
747 last_end = state->end;
750 * | ---- desired range ---- |
753 * Just lock what we found and keep going
755 if (state->start == start && state->end <= end) {
756 struct rb_node *next_node;
757 if (state->state & exclusive_bits) {
758 *failed_start = state->start;
763 set_state_bits(tree, state, &bits);
765 cache_state(state, cached_state);
766 merge_state(tree, state);
767 if (last_end == (u64)-1)
770 start = last_end + 1;
771 next_node = rb_next(&state->rb_node);
772 if (next_node && start < end && prealloc && !need_resched()) {
773 state = rb_entry(next_node, struct extent_state,
775 if (state->start == start)
782 * | ---- desired range ---- |
785 * | ------------- state -------------- |
787 * We need to split the extent we found, and may flip bits on
790 * If the extent we found extends past our
791 * range, we just split and search again. It'll get split
792 * again the next time though.
794 * If the extent we found is inside our range, we set the
797 if (state->start < start) {
798 if (state->state & exclusive_bits) {
799 *failed_start = start;
804 prealloc = alloc_extent_state_atomic(prealloc);
806 err = split_state(tree, state, prealloc, start);
807 BUG_ON(err == -EEXIST);
811 if (state->end <= end) {
812 set_state_bits(tree, state, &bits);
813 cache_state(state, cached_state);
814 merge_state(tree, state);
815 if (last_end == (u64)-1)
817 start = last_end + 1;
822 * | ---- desired range ---- |
823 * | state | or | state |
825 * There's a hole, we need to insert something in it and
826 * ignore the extent we found.
828 if (state->start > start) {
830 if (end < last_start)
833 this_end = last_start - 1;
835 prealloc = alloc_extent_state_atomic(prealloc);
839 * Avoid to free 'prealloc' if it can be merged with
842 err = insert_state(tree, prealloc, start, this_end,
844 BUG_ON(err == -EEXIST);
846 free_extent_state(prealloc);
850 cache_state(prealloc, cached_state);
852 start = this_end + 1;
856 * | ---- desired range ---- |
858 * We need to split the extent, and set the bit
861 if (state->start <= end && state->end > end) {
862 if (state->state & exclusive_bits) {
863 *failed_start = start;
868 prealloc = alloc_extent_state_atomic(prealloc);
870 err = split_state(tree, state, prealloc, end + 1);
871 BUG_ON(err == -EEXIST);
873 set_state_bits(tree, prealloc, &bits);
874 cache_state(prealloc, cached_state);
875 merge_state(tree, prealloc);
883 spin_unlock(&tree->lock);
885 free_extent_state(prealloc);
892 spin_unlock(&tree->lock);
893 if (mask & __GFP_WAIT)
898 /* wrappers around set/clear extent bit */
899 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
902 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
906 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
907 int bits, gfp_t mask)
909 return set_extent_bit(tree, start, end, bits, 0, NULL,
913 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
914 int bits, gfp_t mask)
916 return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
919 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
920 struct extent_state **cached_state, gfp_t mask)
922 return set_extent_bit(tree, start, end,
923 EXTENT_DELALLOC | EXTENT_DIRTY | EXTENT_UPTODATE,
924 0, NULL, cached_state, mask);
927 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
930 return clear_extent_bit(tree, start, end,
931 EXTENT_DIRTY | EXTENT_DELALLOC |
932 EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
935 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
938 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
942 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
943 struct extent_state **cached_state, gfp_t mask)
945 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0,
946 NULL, cached_state, mask);
949 static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
950 u64 end, struct extent_state **cached_state,
953 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
958 * either insert or lock state struct between start and end use mask to tell
959 * us if waiting is desired.
961 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
962 int bits, struct extent_state **cached_state, gfp_t mask)
967 err = set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
968 EXTENT_LOCKED, &failed_start,
970 if (err == -EEXIST && (mask & __GFP_WAIT)) {
971 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
972 start = failed_start;
976 WARN_ON(start > end);
981 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
983 return lock_extent_bits(tree, start, end, 0, NULL, mask);
986 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
992 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
993 &failed_start, NULL, mask);
994 if (err == -EEXIST) {
995 if (failed_start > start)
996 clear_extent_bit(tree, start, failed_start - 1,
997 EXTENT_LOCKED, 1, 0, NULL, mask);
1003 int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
1004 struct extent_state **cached, gfp_t mask)
1006 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
1010 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
1012 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
1017 * helper function to set both pages and extents in the tree writeback
1019 static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1021 unsigned long index = start >> PAGE_CACHE_SHIFT;
1022 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1025 while (index <= end_index) {
1026 page = find_get_page(tree->mapping, index);
1028 set_page_writeback(page);
1029 page_cache_release(page);
1035 /* find the first state struct with 'bits' set after 'start', and
1036 * return it. tree->lock must be held. NULL will returned if
1037 * nothing was found after 'start'
1039 struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
1040 u64 start, int bits)
1042 struct rb_node *node;
1043 struct extent_state *state;
1046 * this search will find all the extents that end after
1049 node = tree_search(tree, start);
1054 state = rb_entry(node, struct extent_state, rb_node);
1055 if (state->end >= start && (state->state & bits))
1058 node = rb_next(node);
1067 * find the first offset in the io tree with 'bits' set. zero is
1068 * returned if we find something, and *start_ret and *end_ret are
1069 * set to reflect the state struct that was found.
1071 * If nothing was found, 1 is returned, < 0 on error
1073 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1074 u64 *start_ret, u64 *end_ret, int bits)
1076 struct extent_state *state;
1079 spin_lock(&tree->lock);
1080 state = find_first_extent_bit_state(tree, start, bits);
1082 *start_ret = state->start;
1083 *end_ret = state->end;
1086 spin_unlock(&tree->lock);
1091 * find a contiguous range of bytes in the file marked as delalloc, not
1092 * more than 'max_bytes'. start and end are used to return the range,
1094 * 1 is returned if we find something, 0 if nothing was in the tree
1096 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1097 u64 *start, u64 *end, u64 max_bytes,
1098 struct extent_state **cached_state)
1100 struct rb_node *node;
1101 struct extent_state *state;
1102 u64 cur_start = *start;
1104 u64 total_bytes = 0;
1106 spin_lock(&tree->lock);
1109 * this search will find all the extents that end after
1112 node = tree_search(tree, cur_start);
1120 state = rb_entry(node, struct extent_state, rb_node);
1121 if (found && (state->start != cur_start ||
1122 (state->state & EXTENT_BOUNDARY))) {
1125 if (!(state->state & EXTENT_DELALLOC)) {
1131 *start = state->start;
1132 *cached_state = state;
1133 atomic_inc(&state->refs);
1137 cur_start = state->end + 1;
1138 node = rb_next(node);
1141 total_bytes += state->end - state->start + 1;
1142 if (total_bytes >= max_bytes)
1146 spin_unlock(&tree->lock);
1150 static noinline int __unlock_for_delalloc(struct inode *inode,
1151 struct page *locked_page,
1155 struct page *pages[16];
1156 unsigned long index = start >> PAGE_CACHE_SHIFT;
1157 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1158 unsigned long nr_pages = end_index - index + 1;
1161 if (index == locked_page->index && end_index == index)
1164 while (nr_pages > 0) {
1165 ret = find_get_pages_contig(inode->i_mapping, index,
1166 min_t(unsigned long, nr_pages,
1167 ARRAY_SIZE(pages)), pages);
1168 for (i = 0; i < ret; i++) {
1169 if (pages[i] != locked_page)
1170 unlock_page(pages[i]);
1171 page_cache_release(pages[i]);
1180 static noinline int lock_delalloc_pages(struct inode *inode,
1181 struct page *locked_page,
1185 unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
1186 unsigned long start_index = index;
1187 unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
1188 unsigned long pages_locked = 0;
1189 struct page *pages[16];
1190 unsigned long nrpages;
1194 /* the caller is responsible for locking the start index */
1195 if (index == locked_page->index && index == end_index)
1198 /* skip the page at the start index */
1199 nrpages = end_index - index + 1;
1200 while (nrpages > 0) {
1201 ret = find_get_pages_contig(inode->i_mapping, index,
1202 min_t(unsigned long,
1203 nrpages, ARRAY_SIZE(pages)), pages);
1208 /* now we have an array of pages, lock them all */
1209 for (i = 0; i < ret; i++) {
1211 * the caller is taking responsibility for
1214 if (pages[i] != locked_page) {
1215 lock_page(pages[i]);
1216 if (!PageDirty(pages[i]) ||
1217 pages[i]->mapping != inode->i_mapping) {
1219 unlock_page(pages[i]);
1220 page_cache_release(pages[i]);
1224 page_cache_release(pages[i]);
1233 if (ret && pages_locked) {
1234 __unlock_for_delalloc(inode, locked_page,
1236 ((u64)(start_index + pages_locked - 1)) <<
1243 * find a contiguous range of bytes in the file marked as delalloc, not
1244 * more than 'max_bytes'. start and end are used to return the range,
1246 * 1 is returned if we find something, 0 if nothing was in the tree
1248 static noinline u64 find_lock_delalloc_range(struct inode *inode,
1249 struct extent_io_tree *tree,
1250 struct page *locked_page,
1251 u64 *start, u64 *end,
1257 struct extent_state *cached_state = NULL;
1262 /* step one, find a bunch of delalloc bytes starting at start */
1263 delalloc_start = *start;
1265 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1266 max_bytes, &cached_state);
1267 if (!found || delalloc_end <= *start) {
1268 *start = delalloc_start;
1269 *end = delalloc_end;
1270 free_extent_state(cached_state);
1275 * start comes from the offset of locked_page. We have to lock
1276 * pages in order, so we can't process delalloc bytes before
1279 if (delalloc_start < *start)
1280 delalloc_start = *start;
1283 * make sure to limit the number of pages we try to lock down
1286 if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1287 delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
1289 /* step two, lock all the pages after the page that has start */
1290 ret = lock_delalloc_pages(inode, locked_page,
1291 delalloc_start, delalloc_end);
1292 if (ret == -EAGAIN) {
1293 /* some of the pages are gone, lets avoid looping by
1294 * shortening the size of the delalloc range we're searching
1296 free_extent_state(cached_state);
1298 unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
1299 max_bytes = PAGE_CACHE_SIZE - offset;
1309 /* step three, lock the state bits for the whole range */
1310 lock_extent_bits(tree, delalloc_start, delalloc_end,
1311 0, &cached_state, GFP_NOFS);
1313 /* then test to make sure it is all still delalloc */
1314 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1315 EXTENT_DELALLOC, 1, cached_state);
1317 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1318 &cached_state, GFP_NOFS);
1319 __unlock_for_delalloc(inode, locked_page,
1320 delalloc_start, delalloc_end);
1324 free_extent_state(cached_state);
1325 *start = delalloc_start;
1326 *end = delalloc_end;
1331 int extent_clear_unlock_delalloc(struct inode *inode,
1332 struct extent_io_tree *tree,
1333 u64 start, u64 end, struct page *locked_page,
1337 struct page *pages[16];
1338 unsigned long index = start >> PAGE_CACHE_SHIFT;
1339 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1340 unsigned long nr_pages = end_index - index + 1;
1344 if (op & EXTENT_CLEAR_UNLOCK)
1345 clear_bits |= EXTENT_LOCKED;
1346 if (op & EXTENT_CLEAR_DIRTY)
1347 clear_bits |= EXTENT_DIRTY;
1349 if (op & EXTENT_CLEAR_DELALLOC)
1350 clear_bits |= EXTENT_DELALLOC;
1352 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1353 if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
1354 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
1355 EXTENT_SET_PRIVATE2)))
1358 while (nr_pages > 0) {
1359 ret = find_get_pages_contig(inode->i_mapping, index,
1360 min_t(unsigned long,
1361 nr_pages, ARRAY_SIZE(pages)), pages);
1362 for (i = 0; i < ret; i++) {
1364 if (op & EXTENT_SET_PRIVATE2)
1365 SetPagePrivate2(pages[i]);
1367 if (pages[i] == locked_page) {
1368 page_cache_release(pages[i]);
1371 if (op & EXTENT_CLEAR_DIRTY)
1372 clear_page_dirty_for_io(pages[i]);
1373 if (op & EXTENT_SET_WRITEBACK)
1374 set_page_writeback(pages[i]);
1375 if (op & EXTENT_END_WRITEBACK)
1376 end_page_writeback(pages[i]);
1377 if (op & EXTENT_CLEAR_UNLOCK_PAGE)
1378 unlock_page(pages[i]);
1379 page_cache_release(pages[i]);
1389 * count the number of bytes in the tree that have a given bit(s)
1390 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1391 * cached. The total number found is returned.
1393 u64 count_range_bits(struct extent_io_tree *tree,
1394 u64 *start, u64 search_end, u64 max_bytes,
1395 unsigned long bits, int contig)
1397 struct rb_node *node;
1398 struct extent_state *state;
1399 u64 cur_start = *start;
1400 u64 total_bytes = 0;
1404 if (search_end <= cur_start) {
1409 spin_lock(&tree->lock);
1410 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1411 total_bytes = tree->dirty_bytes;
1415 * this search will find all the extents that end after
1418 node = tree_search(tree, cur_start);
1423 state = rb_entry(node, struct extent_state, rb_node);
1424 if (state->start > search_end)
1426 if (contig && found && state->start > last + 1)
1428 if (state->end >= cur_start && (state->state & bits) == bits) {
1429 total_bytes += min(search_end, state->end) + 1 -
1430 max(cur_start, state->start);
1431 if (total_bytes >= max_bytes)
1434 *start = max(cur_start, state->start);
1438 } else if (contig && found) {
1441 node = rb_next(node);
1446 spin_unlock(&tree->lock);
1451 * set the private field for a given byte offset in the tree. If there isn't
1452 * an extent_state there already, this does nothing.
1454 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1456 struct rb_node *node;
1457 struct extent_state *state;
1460 spin_lock(&tree->lock);
1462 * this search will find all the extents that end after
1465 node = tree_search(tree, start);
1470 state = rb_entry(node, struct extent_state, rb_node);
1471 if (state->start != start) {
1475 state->private = private;
1477 spin_unlock(&tree->lock);
1481 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1483 struct rb_node *node;
1484 struct extent_state *state;
1487 spin_lock(&tree->lock);
1489 * this search will find all the extents that end after
1492 node = tree_search(tree, start);
1497 state = rb_entry(node, struct extent_state, rb_node);
1498 if (state->start != start) {
1502 *private = state->private;
1504 spin_unlock(&tree->lock);
1509 * searches a range in the state tree for a given mask.
1510 * If 'filled' == 1, this returns 1 only if every extent in the tree
1511 * has the bits set. Otherwise, 1 is returned if any bit in the
1512 * range is found set.
1514 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1515 int bits, int filled, struct extent_state *cached)
1517 struct extent_state *state = NULL;
1518 struct rb_node *node;
1521 spin_lock(&tree->lock);
1522 if (cached && cached->tree && cached->start <= start &&
1523 cached->end > start)
1524 node = &cached->rb_node;
1526 node = tree_search(tree, start);
1527 while (node && start <= end) {
1528 state = rb_entry(node, struct extent_state, rb_node);
1530 if (filled && state->start > start) {
1535 if (state->start > end)
1538 if (state->state & bits) {
1542 } else if (filled) {
1547 if (state->end == (u64)-1)
1550 start = state->end + 1;
1553 node = rb_next(node);
1560 spin_unlock(&tree->lock);
1565 * helper function to set a given page up to date if all the
1566 * extents in the tree for that page are up to date
1568 static int check_page_uptodate(struct extent_io_tree *tree,
1571 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1572 u64 end = start + PAGE_CACHE_SIZE - 1;
1573 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1574 SetPageUptodate(page);
1579 * helper function to unlock a page if all the extents in the tree
1580 * for that page are unlocked
1582 static int check_page_locked(struct extent_io_tree *tree,
1585 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1586 u64 end = start + PAGE_CACHE_SIZE - 1;
1587 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
1593 * helper function to end page writeback if all the extents
1594 * in the tree for that page are done with writeback
1596 static int check_page_writeback(struct extent_io_tree *tree,
1599 end_page_writeback(page);
1604 * When IO fails, either with EIO or csum verification fails, we
1605 * try other mirrors that might have a good copy of the data. This
1606 * io_failure_record is used to record state as we go through all the
1607 * mirrors. If another mirror has good data, the page is set up to date
1608 * and things continue. If a good mirror can't be found, the original
1609 * bio end_io callback is called to indicate things have failed.
1611 struct io_failure_record {
1616 unsigned long bio_flags;
1622 static int free_io_failure(struct inode *inode, struct io_failure_record *rec,
1627 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1629 set_state_private(failure_tree, rec->start, 0);
1630 ret = clear_extent_bits(failure_tree, rec->start,
1631 rec->start + rec->len - 1,
1632 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
1637 ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
1638 rec->start + rec->len - 1,
1639 EXTENT_DAMAGED, GFP_NOFS);
1648 static void repair_io_failure_callback(struct bio *bio, int err)
1650 complete(bio->bi_private);
1654 * this bypasses the standard btrfs submit functions deliberately, as
1655 * the standard behavior is to write all copies in a raid setup. here we only
1656 * want to write the one bad copy. so we do the mapping for ourselves and issue
1657 * submit_bio directly.
1658 * to avoid any synchonization issues, wait for the data after writing, which
1659 * actually prevents the read that triggered the error from finishing.
1660 * currently, there can be no more than two copies of every data bit. thus,
1661 * exactly one rewrite is required.
1663 int repair_io_failure(struct btrfs_mapping_tree *map_tree, u64 start,
1664 u64 length, u64 logical, struct page *page,
1668 struct btrfs_device *dev;
1669 DECLARE_COMPLETION_ONSTACK(compl);
1672 struct btrfs_bio *bbio = NULL;
1675 BUG_ON(!mirror_num);
1677 bio = bio_alloc(GFP_NOFS, 1);
1680 bio->bi_private = &compl;
1681 bio->bi_end_io = repair_io_failure_callback;
1683 map_length = length;
1685 ret = btrfs_map_block(map_tree, WRITE, logical,
1686 &map_length, &bbio, mirror_num);
1691 BUG_ON(mirror_num != bbio->mirror_num);
1692 sector = bbio->stripes[mirror_num-1].physical >> 9;
1693 bio->bi_sector = sector;
1694 dev = bbio->stripes[mirror_num-1].dev;
1696 if (!dev || !dev->bdev || !dev->writeable) {
1700 bio->bi_bdev = dev->bdev;
1701 bio_add_page(bio, page, length, start-page_offset(page));
1702 submit_bio(WRITE_SYNC, bio);
1703 wait_for_completion(&compl);
1705 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
1706 /* try to remap that extent elsewhere? */
1711 printk(KERN_INFO "btrfs read error corrected: ino %lu off %llu (dev %s "
1712 "sector %llu)\n", page->mapping->host->i_ino, start,
1720 * each time an IO finishes, we do a fast check in the IO failure tree
1721 * to see if we need to process or clean up an io_failure_record
1723 static int clean_io_failure(u64 start, struct page *page)
1726 u64 private_failure;
1727 struct io_failure_record *failrec;
1728 struct btrfs_mapping_tree *map_tree;
1729 struct extent_state *state;
1733 struct inode *inode = page->mapping->host;
1736 ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
1737 (u64)-1, 1, EXTENT_DIRTY, 0);
1741 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree, start,
1746 failrec = (struct io_failure_record *)(unsigned long) private_failure;
1747 BUG_ON(!failrec->this_mirror);
1749 if (failrec->in_validation) {
1750 /* there was no real error, just free the record */
1751 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
1757 spin_lock(&BTRFS_I(inode)->io_tree.lock);
1758 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
1761 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
1763 if (state && state->start == failrec->start) {
1764 map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree;
1765 num_copies = btrfs_num_copies(map_tree, failrec->logical,
1767 if (num_copies > 1) {
1768 ret = repair_io_failure(map_tree, start, failrec->len,
1769 failrec->logical, page,
1770 failrec->failed_mirror);
1777 ret = free_io_failure(inode, failrec, did_repair);
1783 * this is a generic handler for readpage errors (default
1784 * readpage_io_failed_hook). if other copies exist, read those and write back
1785 * good data to the failed position. does not investigate in remapping the
1786 * failed extent elsewhere, hoping the device will be smart enough to do this as
1790 static int bio_readpage_error(struct bio *failed_bio, struct page *page,
1791 u64 start, u64 end, int failed_mirror,
1792 struct extent_state *state)
1794 struct io_failure_record *failrec = NULL;
1796 struct extent_map *em;
1797 struct inode *inode = page->mapping->host;
1798 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1799 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
1800 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1807 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
1809 ret = get_state_private(failure_tree, start, &private);
1811 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
1814 failrec->start = start;
1815 failrec->len = end - start + 1;
1816 failrec->this_mirror = 0;
1817 failrec->bio_flags = 0;
1818 failrec->in_validation = 0;
1820 read_lock(&em_tree->lock);
1821 em = lookup_extent_mapping(em_tree, start, failrec->len);
1823 read_unlock(&em_tree->lock);
1828 if (em->start > start || em->start + em->len < start) {
1829 free_extent_map(em);
1832 read_unlock(&em_tree->lock);
1834 if (!em || IS_ERR(em)) {
1838 logical = start - em->start;
1839 logical = em->block_start + logical;
1840 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
1841 logical = em->block_start;
1842 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
1843 extent_set_compress_type(&failrec->bio_flags,
1846 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
1847 "len=%llu\n", logical, start, failrec->len);
1848 failrec->logical = logical;
1849 free_extent_map(em);
1851 /* set the bits in the private failure tree */
1852 ret = set_extent_bits(failure_tree, start, end,
1853 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
1855 ret = set_state_private(failure_tree, start,
1856 (u64)(unsigned long)failrec);
1857 /* set the bits in the inode's tree */
1859 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED,
1866 failrec = (struct io_failure_record *)(unsigned long)private;
1867 pr_debug("bio_readpage_error: (found) logical=%llu, "
1868 "start=%llu, len=%llu, validation=%d\n",
1869 failrec->logical, failrec->start, failrec->len,
1870 failrec->in_validation);
1872 * when data can be on disk more than twice, add to failrec here
1873 * (e.g. with a list for failed_mirror) to make
1874 * clean_io_failure() clean all those errors at once.
1877 num_copies = btrfs_num_copies(
1878 &BTRFS_I(inode)->root->fs_info->mapping_tree,
1879 failrec->logical, failrec->len);
1880 if (num_copies == 1) {
1882 * we only have a single copy of the data, so don't bother with
1883 * all the retry and error correction code that follows. no
1884 * matter what the error is, it is very likely to persist.
1886 pr_debug("bio_readpage_error: cannot repair, num_copies == 1. "
1887 "state=%p, num_copies=%d, next_mirror %d, "
1888 "failed_mirror %d\n", state, num_copies,
1889 failrec->this_mirror, failed_mirror);
1890 free_io_failure(inode, failrec, 0);
1895 spin_lock(&tree->lock);
1896 state = find_first_extent_bit_state(tree, failrec->start,
1898 if (state && state->start != failrec->start)
1900 spin_unlock(&tree->lock);
1904 * there are two premises:
1905 * a) deliver good data to the caller
1906 * b) correct the bad sectors on disk
1908 if (failed_bio->bi_vcnt > 1) {
1910 * to fulfill b), we need to know the exact failing sectors, as
1911 * we don't want to rewrite any more than the failed ones. thus,
1912 * we need separate read requests for the failed bio
1914 * if the following BUG_ON triggers, our validation request got
1915 * merged. we need separate requests for our algorithm to work.
1917 BUG_ON(failrec->in_validation);
1918 failrec->in_validation = 1;
1919 failrec->this_mirror = failed_mirror;
1920 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
1923 * we're ready to fulfill a) and b) alongside. get a good copy
1924 * of the failed sector and if we succeed, we have setup
1925 * everything for repair_io_failure to do the rest for us.
1927 if (failrec->in_validation) {
1928 BUG_ON(failrec->this_mirror != failed_mirror);
1929 failrec->in_validation = 0;
1930 failrec->this_mirror = 0;
1932 failrec->failed_mirror = failed_mirror;
1933 failrec->this_mirror++;
1934 if (failrec->this_mirror == failed_mirror)
1935 failrec->this_mirror++;
1936 read_mode = READ_SYNC;
1939 if (!state || failrec->this_mirror > num_copies) {
1940 pr_debug("bio_readpage_error: (fail) state=%p, num_copies=%d, "
1941 "next_mirror %d, failed_mirror %d\n", state,
1942 num_copies, failrec->this_mirror, failed_mirror);
1943 free_io_failure(inode, failrec, 0);
1947 bio = bio_alloc(GFP_NOFS, 1);
1948 bio->bi_private = state;
1949 bio->bi_end_io = failed_bio->bi_end_io;
1950 bio->bi_sector = failrec->logical >> 9;
1951 bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
1954 bio_add_page(bio, page, failrec->len, start - page_offset(page));
1956 pr_debug("bio_readpage_error: submitting new read[%#x] to "
1957 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode,
1958 failrec->this_mirror, num_copies, failrec->in_validation);
1960 tree->ops->submit_bio_hook(inode, read_mode, bio, failrec->this_mirror,
1961 failrec->bio_flags, 0);
1965 /* lots and lots of room for performance fixes in the end_bio funcs */
1968 * after a writepage IO is done, we need to:
1969 * clear the uptodate bits on error
1970 * clear the writeback bits in the extent tree for this IO
1971 * end_page_writeback if the page has no more pending IO
1973 * Scheduling is not allowed, so the extent state tree is expected
1974 * to have one and only one object corresponding to this IO.
1976 static void end_bio_extent_writepage(struct bio *bio, int err)
1978 int uptodate = err == 0;
1979 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1980 struct extent_io_tree *tree;
1987 struct page *page = bvec->bv_page;
1988 tree = &BTRFS_I(page->mapping->host)->io_tree;
1990 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
1992 end = start + bvec->bv_len - 1;
1994 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
1999 if (--bvec >= bio->bi_io_vec)
2000 prefetchw(&bvec->bv_page->flags);
2001 if (tree->ops && tree->ops->writepage_end_io_hook) {
2002 ret = tree->ops->writepage_end_io_hook(page, start,
2003 end, NULL, uptodate);
2008 if (!uptodate && tree->ops &&
2009 tree->ops->writepage_io_failed_hook) {
2010 ret = tree->ops->writepage_io_failed_hook(bio, page,
2013 uptodate = (err == 0);
2019 clear_extent_uptodate(tree, start, end, NULL, GFP_NOFS);
2020 ClearPageUptodate(page);
2025 end_page_writeback(page);
2027 check_page_writeback(tree, page);
2028 } while (bvec >= bio->bi_io_vec);
2034 * after a readpage IO is done, we need to:
2035 * clear the uptodate bits on error
2036 * set the uptodate bits if things worked
2037 * set the page up to date if all extents in the tree are uptodate
2038 * clear the lock bit in the extent tree
2039 * unlock the page if there are no other extents locked for it
2041 * Scheduling is not allowed, so the extent state tree is expected
2042 * to have one and only one object corresponding to this IO.
2044 static void end_bio_extent_readpage(struct bio *bio, int err)
2046 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
2047 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
2048 struct bio_vec *bvec = bio->bi_io_vec;
2049 struct extent_io_tree *tree;
2059 struct page *page = bvec->bv_page;
2060 struct extent_state *cached = NULL;
2061 struct extent_state *state;
2063 pr_debug("end_bio_extent_readpage: bi_vcnt=%d, idx=%d, err=%d, "
2064 "mirror=%ld\n", bio->bi_vcnt, bio->bi_idx, err,
2065 (long int)bio->bi_bdev);
2066 tree = &BTRFS_I(page->mapping->host)->io_tree;
2068 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
2070 end = start + bvec->bv_len - 1;
2072 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
2077 if (++bvec <= bvec_end)
2078 prefetchw(&bvec->bv_page->flags);
2080 spin_lock(&tree->lock);
2081 state = find_first_extent_bit_state(tree, start, EXTENT_LOCKED);
2082 if (state && state->start == start) {
2084 * take a reference on the state, unlock will drop
2087 cache_state(state, &cached);
2089 spin_unlock(&tree->lock);
2091 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
2092 ret = tree->ops->readpage_end_io_hook(page, start, end,
2097 clean_io_failure(start, page);
2101 failed_mirror = (u64)bio->bi_bdev;
2102 if (tree->ops && tree->ops->readpage_io_failed_hook)
2103 ret = tree->ops->readpage_io_failed_hook(
2104 bio, page, start, end,
2105 failed_mirror, NULL);
2107 ret = bio_readpage_error(bio, page, start, end,
2108 failed_mirror, NULL);
2111 test_bit(BIO_UPTODATE, &bio->bi_flags);
2114 uncache_state(&cached);
2120 set_extent_uptodate(tree, start, end, &cached,
2123 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2127 SetPageUptodate(page);
2129 ClearPageUptodate(page);
2135 check_page_uptodate(tree, page);
2137 ClearPageUptodate(page);
2140 check_page_locked(tree, page);
2142 } while (bvec <= bvec_end);
2148 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2153 bio = bio_alloc(gfp_flags, nr_vecs);
2155 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2156 while (!bio && (nr_vecs /= 2))
2157 bio = bio_alloc(gfp_flags, nr_vecs);
2162 bio->bi_bdev = bdev;
2163 bio->bi_sector = first_sector;
2168 static int submit_one_bio(int rw, struct bio *bio, int mirror_num,
2169 unsigned long bio_flags)
2172 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2173 struct page *page = bvec->bv_page;
2174 struct extent_io_tree *tree = bio->bi_private;
2177 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
2179 bio->bi_private = NULL;
2183 if (tree->ops && tree->ops->submit_bio_hook)
2184 ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
2185 mirror_num, bio_flags, start);
2187 submit_bio(rw, bio);
2189 if (bio_flagged(bio, BIO_EOPNOTSUPP))
2195 static int submit_extent_page(int rw, struct extent_io_tree *tree,
2196 struct page *page, sector_t sector,
2197 size_t size, unsigned long offset,
2198 struct block_device *bdev,
2199 struct bio **bio_ret,
2200 unsigned long max_pages,
2201 bio_end_io_t end_io_func,
2203 unsigned long prev_bio_flags,
2204 unsigned long bio_flags)
2210 int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
2211 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2212 size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
2214 if (bio_ret && *bio_ret) {
2217 contig = bio->bi_sector == sector;
2219 contig = bio->bi_sector + (bio->bi_size >> 9) ==
2222 if (prev_bio_flags != bio_flags || !contig ||
2223 (tree->ops && tree->ops->merge_bio_hook &&
2224 tree->ops->merge_bio_hook(page, offset, page_size, bio,
2226 bio_add_page(bio, page, page_size, offset) < page_size) {
2227 ret = submit_one_bio(rw, bio, mirror_num,
2234 if (this_compressed)
2237 nr = bio_get_nr_vecs(bdev);
2239 bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
2243 bio_add_page(bio, page, page_size, offset);
2244 bio->bi_end_io = end_io_func;
2245 bio->bi_private = tree;
2250 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
2255 void set_page_extent_mapped(struct page *page)
2257 if (!PagePrivate(page)) {
2258 SetPagePrivate(page);
2259 page_cache_get(page);
2260 set_page_private(page, EXTENT_PAGE_PRIVATE);
2264 static void set_page_extent_head(struct page *page, unsigned long len)
2266 WARN_ON(!PagePrivate(page));
2267 set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
2271 * basic readpage implementation. Locked extent state structs are inserted
2272 * into the tree that are removed when the IO is done (by the end_io
2275 static int __extent_read_full_page(struct extent_io_tree *tree,
2277 get_extent_t *get_extent,
2278 struct bio **bio, int mirror_num,
2279 unsigned long *bio_flags)
2281 struct inode *inode = page->mapping->host;
2282 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2283 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2287 u64 last_byte = i_size_read(inode);
2291 struct extent_map *em;
2292 struct block_device *bdev;
2293 struct btrfs_ordered_extent *ordered;
2296 size_t pg_offset = 0;
2298 size_t disk_io_size;
2299 size_t blocksize = inode->i_sb->s_blocksize;
2300 unsigned long this_bio_flag = 0;
2302 set_page_extent_mapped(page);
2304 if (!PageUptodate(page)) {
2305 if (cleancache_get_page(page) == 0) {
2306 BUG_ON(blocksize != PAGE_SIZE);
2313 lock_extent(tree, start, end, GFP_NOFS);
2314 ordered = btrfs_lookup_ordered_extent(inode, start);
2317 unlock_extent(tree, start, end, GFP_NOFS);
2318 btrfs_start_ordered_extent(inode, ordered, 1);
2319 btrfs_put_ordered_extent(ordered);
2322 if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
2324 size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
2327 iosize = PAGE_CACHE_SIZE - zero_offset;
2328 userpage = kmap_atomic(page, KM_USER0);
2329 memset(userpage + zero_offset, 0, iosize);
2330 flush_dcache_page(page);
2331 kunmap_atomic(userpage, KM_USER0);
2334 while (cur <= end) {
2335 if (cur >= last_byte) {
2337 struct extent_state *cached = NULL;
2339 iosize = PAGE_CACHE_SIZE - pg_offset;
2340 userpage = kmap_atomic(page, KM_USER0);
2341 memset(userpage + pg_offset, 0, iosize);
2342 flush_dcache_page(page);
2343 kunmap_atomic(userpage, KM_USER0);
2344 set_extent_uptodate(tree, cur, cur + iosize - 1,
2346 unlock_extent_cached(tree, cur, cur + iosize - 1,
2350 em = get_extent(inode, page, pg_offset, cur,
2352 if (IS_ERR_OR_NULL(em)) {
2354 unlock_extent(tree, cur, end, GFP_NOFS);
2357 extent_offset = cur - em->start;
2358 BUG_ON(extent_map_end(em) <= cur);
2361 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2362 this_bio_flag = EXTENT_BIO_COMPRESSED;
2363 extent_set_compress_type(&this_bio_flag,
2367 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2368 cur_end = min(extent_map_end(em) - 1, end);
2369 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2370 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2371 disk_io_size = em->block_len;
2372 sector = em->block_start >> 9;
2374 sector = (em->block_start + extent_offset) >> 9;
2375 disk_io_size = iosize;
2378 block_start = em->block_start;
2379 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2380 block_start = EXTENT_MAP_HOLE;
2381 free_extent_map(em);
2384 /* we've found a hole, just zero and go on */
2385 if (block_start == EXTENT_MAP_HOLE) {
2387 struct extent_state *cached = NULL;
2389 userpage = kmap_atomic(page, KM_USER0);
2390 memset(userpage + pg_offset, 0, iosize);
2391 flush_dcache_page(page);
2392 kunmap_atomic(userpage, KM_USER0);
2394 set_extent_uptodate(tree, cur, cur + iosize - 1,
2396 unlock_extent_cached(tree, cur, cur + iosize - 1,
2399 pg_offset += iosize;
2402 /* the get_extent function already copied into the page */
2403 if (test_range_bit(tree, cur, cur_end,
2404 EXTENT_UPTODATE, 1, NULL)) {
2405 check_page_uptodate(tree, page);
2406 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2408 pg_offset += iosize;
2411 /* we have an inline extent but it didn't get marked up
2412 * to date. Error out
2414 if (block_start == EXTENT_MAP_INLINE) {
2416 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2418 pg_offset += iosize;
2423 if (tree->ops && tree->ops->readpage_io_hook) {
2424 ret = tree->ops->readpage_io_hook(page, cur,
2428 unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
2430 ret = submit_extent_page(READ, tree, page,
2431 sector, disk_io_size, pg_offset,
2433 end_bio_extent_readpage, mirror_num,
2437 *bio_flags = this_bio_flag;
2442 pg_offset += iosize;
2446 if (!PageError(page))
2447 SetPageUptodate(page);
2453 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
2454 get_extent_t *get_extent, int mirror_num)
2456 struct bio *bio = NULL;
2457 unsigned long bio_flags = 0;
2460 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
2463 ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
2467 static noinline void update_nr_written(struct page *page,
2468 struct writeback_control *wbc,
2469 unsigned long nr_written)
2471 wbc->nr_to_write -= nr_written;
2472 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
2473 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
2474 page->mapping->writeback_index = page->index + nr_written;
2478 * the writepage semantics are similar to regular writepage. extent
2479 * records are inserted to lock ranges in the tree, and as dirty areas
2480 * are found, they are marked writeback. Then the lock bits are removed
2481 * and the end_io handler clears the writeback ranges
2483 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
2486 struct inode *inode = page->mapping->host;
2487 struct extent_page_data *epd = data;
2488 struct extent_io_tree *tree = epd->tree;
2489 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2491 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2495 u64 last_byte = i_size_read(inode);
2499 struct extent_state *cached_state = NULL;
2500 struct extent_map *em;
2501 struct block_device *bdev;
2504 size_t pg_offset = 0;
2506 loff_t i_size = i_size_read(inode);
2507 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
2513 unsigned long nr_written = 0;
2515 if (wbc->sync_mode == WB_SYNC_ALL)
2516 write_flags = WRITE_SYNC;
2518 write_flags = WRITE;
2520 trace___extent_writepage(page, inode, wbc);
2522 WARN_ON(!PageLocked(page));
2523 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2524 if (page->index > end_index ||
2525 (page->index == end_index && !pg_offset)) {
2526 page->mapping->a_ops->invalidatepage(page, 0);
2531 if (page->index == end_index) {
2534 userpage = kmap_atomic(page, KM_USER0);
2535 memset(userpage + pg_offset, 0,
2536 PAGE_CACHE_SIZE - pg_offset);
2537 kunmap_atomic(userpage, KM_USER0);
2538 flush_dcache_page(page);
2542 set_page_extent_mapped(page);
2544 delalloc_start = start;
2547 if (!epd->extent_locked) {
2548 u64 delalloc_to_write = 0;
2550 * make sure the wbc mapping index is at least updated
2553 update_nr_written(page, wbc, 0);
2555 while (delalloc_end < page_end) {
2556 nr_delalloc = find_lock_delalloc_range(inode, tree,
2561 if (nr_delalloc == 0) {
2562 delalloc_start = delalloc_end + 1;
2565 tree->ops->fill_delalloc(inode, page, delalloc_start,
2566 delalloc_end, &page_started,
2569 * delalloc_end is already one less than the total
2570 * length, so we don't subtract one from
2573 delalloc_to_write += (delalloc_end - delalloc_start +
2576 delalloc_start = delalloc_end + 1;
2578 if (wbc->nr_to_write < delalloc_to_write) {
2581 if (delalloc_to_write < thresh * 2)
2582 thresh = delalloc_to_write;
2583 wbc->nr_to_write = min_t(u64, delalloc_to_write,
2587 /* did the fill delalloc function already unlock and start
2593 * we've unlocked the page, so we can't update
2594 * the mapping's writeback index, just update
2597 wbc->nr_to_write -= nr_written;
2601 if (tree->ops && tree->ops->writepage_start_hook) {
2602 ret = tree->ops->writepage_start_hook(page, start,
2604 if (ret == -EAGAIN) {
2605 redirty_page_for_writepage(wbc, page);
2606 update_nr_written(page, wbc, nr_written);
2614 * we don't want to touch the inode after unlocking the page,
2615 * so we update the mapping writeback index now
2617 update_nr_written(page, wbc, nr_written + 1);
2620 if (last_byte <= start) {
2621 if (tree->ops && tree->ops->writepage_end_io_hook)
2622 tree->ops->writepage_end_io_hook(page, start,
2627 blocksize = inode->i_sb->s_blocksize;
2629 while (cur <= end) {
2630 if (cur >= last_byte) {
2631 if (tree->ops && tree->ops->writepage_end_io_hook)
2632 tree->ops->writepage_end_io_hook(page, cur,
2636 em = epd->get_extent(inode, page, pg_offset, cur,
2638 if (IS_ERR_OR_NULL(em)) {
2643 extent_offset = cur - em->start;
2644 BUG_ON(extent_map_end(em) <= cur);
2646 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2647 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2648 sector = (em->block_start + extent_offset) >> 9;
2650 block_start = em->block_start;
2651 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
2652 free_extent_map(em);
2656 * compressed and inline extents are written through other
2659 if (compressed || block_start == EXTENT_MAP_HOLE ||
2660 block_start == EXTENT_MAP_INLINE) {
2662 * end_io notification does not happen here for
2663 * compressed extents
2665 if (!compressed && tree->ops &&
2666 tree->ops->writepage_end_io_hook)
2667 tree->ops->writepage_end_io_hook(page, cur,
2670 else if (compressed) {
2671 /* we don't want to end_page_writeback on
2672 * a compressed extent. this happens
2679 pg_offset += iosize;
2682 /* leave this out until we have a page_mkwrite call */
2683 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
2684 EXTENT_DIRTY, 0, NULL)) {
2686 pg_offset += iosize;
2690 if (tree->ops && tree->ops->writepage_io_hook) {
2691 ret = tree->ops->writepage_io_hook(page, cur,
2699 unsigned long max_nr = end_index + 1;
2701 set_range_writeback(tree, cur, cur + iosize - 1);
2702 if (!PageWriteback(page)) {
2703 printk(KERN_ERR "btrfs warning page %lu not "
2704 "writeback, cur %llu end %llu\n",
2705 page->index, (unsigned long long)cur,
2706 (unsigned long long)end);
2709 ret = submit_extent_page(write_flags, tree, page,
2710 sector, iosize, pg_offset,
2711 bdev, &epd->bio, max_nr,
2712 end_bio_extent_writepage,
2718 pg_offset += iosize;
2723 /* make sure the mapping tag for page dirty gets cleared */
2724 set_page_writeback(page);
2725 end_page_writeback(page);
2731 /* drop our reference on any cached states */
2732 free_extent_state(cached_state);
2737 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2738 * @mapping: address space structure to write
2739 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2740 * @writepage: function called for each page
2741 * @data: data passed to writepage function
2743 * If a page is already under I/O, write_cache_pages() skips it, even
2744 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2745 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2746 * and msync() need to guarantee that all the data which was dirty at the time
2747 * the call was made get new I/O started against them. If wbc->sync_mode is
2748 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2749 * existing IO to complete.
2751 static int extent_write_cache_pages(struct extent_io_tree *tree,
2752 struct address_space *mapping,
2753 struct writeback_control *wbc,
2754 writepage_t writepage, void *data,
2755 void (*flush_fn)(void *))
2759 int nr_to_write_done = 0;
2760 struct pagevec pvec;
2763 pgoff_t end; /* Inclusive */
2767 pagevec_init(&pvec, 0);
2768 if (wbc->range_cyclic) {
2769 index = mapping->writeback_index; /* Start from prev offset */
2772 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2773 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2776 if (wbc->sync_mode == WB_SYNC_ALL)
2777 tag = PAGECACHE_TAG_TOWRITE;
2779 tag = PAGECACHE_TAG_DIRTY;
2781 if (wbc->sync_mode == WB_SYNC_ALL)
2782 tag_pages_for_writeback(mapping, index, end);
2783 while (!done && !nr_to_write_done && (index <= end) &&
2784 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
2785 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
2789 for (i = 0; i < nr_pages; i++) {
2790 struct page *page = pvec.pages[i];
2793 * At this point we hold neither mapping->tree_lock nor
2794 * lock on the page itself: the page may be truncated or
2795 * invalidated (changing page->mapping to NULL), or even
2796 * swizzled back from swapper_space to tmpfs file
2799 if (tree->ops && tree->ops->write_cache_pages_lock_hook)
2800 tree->ops->write_cache_pages_lock_hook(page);
2804 if (unlikely(page->mapping != mapping)) {
2809 if (!wbc->range_cyclic && page->index > end) {
2815 if (wbc->sync_mode != WB_SYNC_NONE) {
2816 if (PageWriteback(page))
2818 wait_on_page_writeback(page);
2821 if (PageWriteback(page) ||
2822 !clear_page_dirty_for_io(page)) {
2827 ret = (*writepage)(page, wbc, data);
2829 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
2837 * the filesystem may choose to bump up nr_to_write.
2838 * We have to make sure to honor the new nr_to_write
2841 nr_to_write_done = wbc->nr_to_write <= 0;
2843 pagevec_release(&pvec);
2846 if (!scanned && !done) {
2848 * We hit the last page and there is more work to be done: wrap
2849 * back to the start of the file
2858 static void flush_epd_write_bio(struct extent_page_data *epd)
2862 submit_one_bio(WRITE_SYNC, epd->bio, 0, 0);
2864 submit_one_bio(WRITE, epd->bio, 0, 0);
2869 static noinline void flush_write_bio(void *data)
2871 struct extent_page_data *epd = data;
2872 flush_epd_write_bio(epd);
2875 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
2876 get_extent_t *get_extent,
2877 struct writeback_control *wbc)
2880 struct extent_page_data epd = {
2883 .get_extent = get_extent,
2885 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
2888 ret = __extent_writepage(page, wbc, &epd);
2890 flush_epd_write_bio(&epd);
2894 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
2895 u64 start, u64 end, get_extent_t *get_extent,
2899 struct address_space *mapping = inode->i_mapping;
2901 unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
2904 struct extent_page_data epd = {
2907 .get_extent = get_extent,
2909 .sync_io = mode == WB_SYNC_ALL,
2911 struct writeback_control wbc_writepages = {
2913 .nr_to_write = nr_pages * 2,
2914 .range_start = start,
2915 .range_end = end + 1,
2918 while (start <= end) {
2919 page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
2920 if (clear_page_dirty_for_io(page))
2921 ret = __extent_writepage(page, &wbc_writepages, &epd);
2923 if (tree->ops && tree->ops->writepage_end_io_hook)
2924 tree->ops->writepage_end_io_hook(page, start,
2925 start + PAGE_CACHE_SIZE - 1,
2929 page_cache_release(page);
2930 start += PAGE_CACHE_SIZE;
2933 flush_epd_write_bio(&epd);
2937 int extent_writepages(struct extent_io_tree *tree,
2938 struct address_space *mapping,
2939 get_extent_t *get_extent,
2940 struct writeback_control *wbc)
2943 struct extent_page_data epd = {
2946 .get_extent = get_extent,
2948 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
2951 ret = extent_write_cache_pages(tree, mapping, wbc,
2952 __extent_writepage, &epd,
2954 flush_epd_write_bio(&epd);
2958 int extent_readpages(struct extent_io_tree *tree,
2959 struct address_space *mapping,
2960 struct list_head *pages, unsigned nr_pages,
2961 get_extent_t get_extent)
2963 struct bio *bio = NULL;
2965 unsigned long bio_flags = 0;
2967 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
2968 struct page *page = list_entry(pages->prev, struct page, lru);
2970 prefetchw(&page->flags);
2971 list_del(&page->lru);
2972 if (!add_to_page_cache_lru(page, mapping,
2973 page->index, GFP_NOFS)) {
2974 __extent_read_full_page(tree, page, get_extent,
2975 &bio, 0, &bio_flags);
2977 page_cache_release(page);
2979 BUG_ON(!list_empty(pages));
2981 submit_one_bio(READ, bio, 0, bio_flags);
2986 * basic invalidatepage code, this waits on any locked or writeback
2987 * ranges corresponding to the page, and then deletes any extent state
2988 * records from the tree
2990 int extent_invalidatepage(struct extent_io_tree *tree,
2991 struct page *page, unsigned long offset)
2993 struct extent_state *cached_state = NULL;
2994 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
2995 u64 end = start + PAGE_CACHE_SIZE - 1;
2996 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
2998 start += (offset + blocksize - 1) & ~(blocksize - 1);
3002 lock_extent_bits(tree, start, end, 0, &cached_state, GFP_NOFS);
3003 wait_on_page_writeback(page);
3004 clear_extent_bit(tree, start, end,
3005 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
3006 EXTENT_DO_ACCOUNTING,
3007 1, 1, &cached_state, GFP_NOFS);
3012 * a helper for releasepage, this tests for areas of the page that
3013 * are locked or under IO and drops the related state bits if it is safe
3016 int try_release_extent_state(struct extent_map_tree *map,
3017 struct extent_io_tree *tree, struct page *page,
3020 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
3021 u64 end = start + PAGE_CACHE_SIZE - 1;
3024 if (test_range_bit(tree, start, end,
3025 EXTENT_IOBITS, 0, NULL))
3028 if ((mask & GFP_NOFS) == GFP_NOFS)
3031 * at this point we can safely clear everything except the
3032 * locked bit and the nodatasum bit
3034 ret = clear_extent_bit(tree, start, end,
3035 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
3038 /* if clear_extent_bit failed for enomem reasons,
3039 * we can't allow the release to continue.
3050 * a helper for releasepage. As long as there are no locked extents
3051 * in the range corresponding to the page, both state records and extent
3052 * map records are removed
3054 int try_release_extent_mapping(struct extent_map_tree *map,
3055 struct extent_io_tree *tree, struct page *page,
3058 struct extent_map *em;
3059 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
3060 u64 end = start + PAGE_CACHE_SIZE - 1;
3062 if ((mask & __GFP_WAIT) &&
3063 page->mapping->host->i_size > 16 * 1024 * 1024) {
3065 while (start <= end) {
3066 len = end - start + 1;
3067 write_lock(&map->lock);
3068 em = lookup_extent_mapping(map, start, len);
3069 if (IS_ERR_OR_NULL(em)) {
3070 write_unlock(&map->lock);
3073 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
3074 em->start != start) {
3075 write_unlock(&map->lock);
3076 free_extent_map(em);
3079 if (!test_range_bit(tree, em->start,
3080 extent_map_end(em) - 1,
3081 EXTENT_LOCKED | EXTENT_WRITEBACK,
3083 remove_extent_mapping(map, em);
3084 /* once for the rb tree */
3085 free_extent_map(em);
3087 start = extent_map_end(em);
3088 write_unlock(&map->lock);
3091 free_extent_map(em);
3094 return try_release_extent_state(map, tree, page, mask);
3098 * helper function for fiemap, which doesn't want to see any holes.
3099 * This maps until we find something past 'last'
3101 static struct extent_map *get_extent_skip_holes(struct inode *inode,
3104 get_extent_t *get_extent)
3106 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
3107 struct extent_map *em;
3114 len = last - offset;
3117 len = (len + sectorsize - 1) & ~(sectorsize - 1);
3118 em = get_extent(inode, NULL, 0, offset, len, 0);
3119 if (IS_ERR_OR_NULL(em))
3122 /* if this isn't a hole return it */
3123 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
3124 em->block_start != EXTENT_MAP_HOLE) {
3128 /* this is a hole, advance to the next extent */
3129 offset = extent_map_end(em);
3130 free_extent_map(em);
3137 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3138 __u64 start, __u64 len, get_extent_t *get_extent)
3142 u64 max = start + len;
3146 u64 last_for_get_extent = 0;
3148 u64 isize = i_size_read(inode);
3149 struct btrfs_key found_key;
3150 struct extent_map *em = NULL;
3151 struct extent_state *cached_state = NULL;
3152 struct btrfs_path *path;
3153 struct btrfs_file_extent_item *item;
3158 unsigned long emflags;
3163 path = btrfs_alloc_path();
3166 path->leave_spinning = 1;
3169 * lookup the last file extent. We're not using i_size here
3170 * because there might be preallocation past i_size
3172 ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
3173 path, btrfs_ino(inode), -1, 0);
3175 btrfs_free_path(path);
3180 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3181 struct btrfs_file_extent_item);
3182 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
3183 found_type = btrfs_key_type(&found_key);
3185 /* No extents, but there might be delalloc bits */
3186 if (found_key.objectid != btrfs_ino(inode) ||
3187 found_type != BTRFS_EXTENT_DATA_KEY) {
3188 /* have to trust i_size as the end */
3190 last_for_get_extent = isize;
3193 * remember the start of the last extent. There are a
3194 * bunch of different factors that go into the length of the
3195 * extent, so its much less complex to remember where it started
3197 last = found_key.offset;
3198 last_for_get_extent = last + 1;
3200 btrfs_free_path(path);
3203 * we might have some extents allocated but more delalloc past those
3204 * extents. so, we trust isize unless the start of the last extent is
3209 last_for_get_extent = isize;
3212 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
3213 &cached_state, GFP_NOFS);
3215 em = get_extent_skip_holes(inode, off, last_for_get_extent,
3225 u64 offset_in_extent;
3227 /* break if the extent we found is outside the range */
3228 if (em->start >= max || extent_map_end(em) < off)
3232 * get_extent may return an extent that starts before our
3233 * requested range. We have to make sure the ranges
3234 * we return to fiemap always move forward and don't
3235 * overlap, so adjust the offsets here
3237 em_start = max(em->start, off);
3240 * record the offset from the start of the extent
3241 * for adjusting the disk offset below
3243 offset_in_extent = em_start - em->start;
3244 em_end = extent_map_end(em);
3245 em_len = em_end - em_start;
3246 emflags = em->flags;
3251 * bump off for our next call to get_extent
3253 off = extent_map_end(em);
3257 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
3259 flags |= FIEMAP_EXTENT_LAST;
3260 } else if (em->block_start == EXTENT_MAP_INLINE) {
3261 flags |= (FIEMAP_EXTENT_DATA_INLINE |
3262 FIEMAP_EXTENT_NOT_ALIGNED);
3263 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
3264 flags |= (FIEMAP_EXTENT_DELALLOC |
3265 FIEMAP_EXTENT_UNKNOWN);
3267 disko = em->block_start + offset_in_extent;
3269 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
3270 flags |= FIEMAP_EXTENT_ENCODED;
3272 free_extent_map(em);
3274 if ((em_start >= last) || em_len == (u64)-1 ||
3275 (last == (u64)-1 && isize <= em_end)) {
3276 flags |= FIEMAP_EXTENT_LAST;
3280 /* now scan forward to see if this is really the last extent. */
3281 em = get_extent_skip_holes(inode, off, last_for_get_extent,
3288 flags |= FIEMAP_EXTENT_LAST;
3291 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
3297 free_extent_map(em);
3299 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len,
3300 &cached_state, GFP_NOFS);
3304 inline struct page *extent_buffer_page(struct extent_buffer *eb,
3308 struct address_space *mapping;
3311 return eb->first_page;
3312 i += eb->start >> PAGE_CACHE_SHIFT;
3313 mapping = eb->first_page->mapping;
3318 * extent_buffer_page is only called after pinning the page
3319 * by increasing the reference count. So we know the page must
3320 * be in the radix tree.
3323 p = radix_tree_lookup(&mapping->page_tree, i);
3329 inline unsigned long num_extent_pages(u64 start, u64 len)
3331 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
3332 (start >> PAGE_CACHE_SHIFT);
3335 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
3340 struct extent_buffer *eb = NULL;
3342 unsigned long flags;
3345 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
3350 rwlock_init(&eb->lock);
3351 atomic_set(&eb->write_locks, 0);
3352 atomic_set(&eb->read_locks, 0);
3353 atomic_set(&eb->blocking_readers, 0);
3354 atomic_set(&eb->blocking_writers, 0);
3355 atomic_set(&eb->spinning_readers, 0);
3356 atomic_set(&eb->spinning_writers, 0);
3357 init_waitqueue_head(&eb->write_lock_wq);
3358 init_waitqueue_head(&eb->read_lock_wq);
3361 spin_lock_irqsave(&leak_lock, flags);
3362 list_add(&eb->leak_list, &buffers);
3363 spin_unlock_irqrestore(&leak_lock, flags);
3365 atomic_set(&eb->refs, 1);
3370 static void __free_extent_buffer(struct extent_buffer *eb)
3373 unsigned long flags;
3374 spin_lock_irqsave(&leak_lock, flags);
3375 list_del(&eb->leak_list);
3376 spin_unlock_irqrestore(&leak_lock, flags);
3378 kmem_cache_free(extent_buffer_cache, eb);
3382 * Helper for releasing extent buffer page.
3384 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
3385 unsigned long start_idx)
3387 unsigned long index;
3390 if (!eb->first_page)
3393 index = num_extent_pages(eb->start, eb->len);
3394 if (start_idx >= index)
3399 page = extent_buffer_page(eb, index);
3401 page_cache_release(page);
3402 } while (index != start_idx);
3406 * Helper for releasing the extent buffer.
3408 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
3410 btrfs_release_extent_buffer_page(eb, 0);
3411 __free_extent_buffer(eb);
3414 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
3415 u64 start, unsigned long len,
3418 unsigned long num_pages = num_extent_pages(start, len);
3420 unsigned long index = start >> PAGE_CACHE_SHIFT;
3421 struct extent_buffer *eb;
3422 struct extent_buffer *exists = NULL;
3424 struct address_space *mapping = tree->mapping;
3429 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3430 if (eb && atomic_inc_not_zero(&eb->refs)) {
3432 mark_page_accessed(eb->first_page);
3437 eb = __alloc_extent_buffer(tree, start, len, GFP_NOFS);
3442 eb->first_page = page0;
3445 page_cache_get(page0);
3446 mark_page_accessed(page0);
3447 set_page_extent_mapped(page0);
3448 set_page_extent_head(page0, len);
3449 uptodate = PageUptodate(page0);
3453 for (; i < num_pages; i++, index++) {
3454 p = find_or_create_page(mapping, index, GFP_NOFS);
3459 set_page_extent_mapped(p);
3460 mark_page_accessed(p);
3463 set_page_extent_head(p, len);
3465 set_page_private(p, EXTENT_PAGE_PRIVATE);
3467 if (!PageUptodate(p))
3471 * see below about how we avoid a nasty race with release page
3472 * and why we unlock later
3478 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3480 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
3484 spin_lock(&tree->buffer_lock);
3485 ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
3486 if (ret == -EEXIST) {
3487 exists = radix_tree_lookup(&tree->buffer,
3488 start >> PAGE_CACHE_SHIFT);
3489 /* add one reference for the caller */
3490 atomic_inc(&exists->refs);
3491 spin_unlock(&tree->buffer_lock);
3492 radix_tree_preload_end();
3495 /* add one reference for the tree */
3496 atomic_inc(&eb->refs);
3497 spin_unlock(&tree->buffer_lock);
3498 radix_tree_preload_end();
3501 * there is a race where release page may have
3502 * tried to find this extent buffer in the radix
3503 * but failed. It will tell the VM it is safe to
3504 * reclaim the, and it will clear the page private bit.
3505 * We must make sure to set the page private bit properly
3506 * after the extent buffer is in the radix tree so
3507 * it doesn't get lost
3509 set_page_extent_mapped(eb->first_page);
3510 set_page_extent_head(eb->first_page, eb->len);
3512 unlock_page(eb->first_page);
3516 if (eb->first_page && !page0)
3517 unlock_page(eb->first_page);
3519 if (!atomic_dec_and_test(&eb->refs))
3521 btrfs_release_extent_buffer(eb);
3525 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
3526 u64 start, unsigned long len)
3528 struct extent_buffer *eb;
3531 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3532 if (eb && atomic_inc_not_zero(&eb->refs)) {
3534 mark_page_accessed(eb->first_page);
3542 void free_extent_buffer(struct extent_buffer *eb)
3547 if (!atomic_dec_and_test(&eb->refs))
3553 int clear_extent_buffer_dirty(struct extent_io_tree *tree,
3554 struct extent_buffer *eb)
3557 unsigned long num_pages;
3560 num_pages = num_extent_pages(eb->start, eb->len);
3562 for (i = 0; i < num_pages; i++) {
3563 page = extent_buffer_page(eb, i);
3564 if (!PageDirty(page))
3568 WARN_ON(!PagePrivate(page));
3570 set_page_extent_mapped(page);
3572 set_page_extent_head(page, eb->len);
3574 clear_page_dirty_for_io(page);
3575 spin_lock_irq(&page->mapping->tree_lock);
3576 if (!PageDirty(page)) {
3577 radix_tree_tag_clear(&page->mapping->page_tree,
3579 PAGECACHE_TAG_DIRTY);
3581 spin_unlock_irq(&page->mapping->tree_lock);
3587 int set_extent_buffer_dirty(struct extent_io_tree *tree,
3588 struct extent_buffer *eb)
3591 unsigned long num_pages;
3594 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
3595 num_pages = num_extent_pages(eb->start, eb->len);
3596 for (i = 0; i < num_pages; i++)
3597 __set_page_dirty_nobuffers(extent_buffer_page(eb, i));
3601 static int __eb_straddles_pages(u64 start, u64 len)
3603 if (len < PAGE_CACHE_SIZE)
3605 if (start & (PAGE_CACHE_SIZE - 1))
3607 if ((start + len) & (PAGE_CACHE_SIZE - 1))
3612 static int eb_straddles_pages(struct extent_buffer *eb)
3614 return __eb_straddles_pages(eb->start, eb->len);
3617 int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
3618 struct extent_buffer *eb,
3619 struct extent_state **cached_state)
3623 unsigned long num_pages;
3625 num_pages = num_extent_pages(eb->start, eb->len);
3626 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3628 if (eb_straddles_pages(eb)) {
3629 clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3630 cached_state, GFP_NOFS);
3632 for (i = 0; i < num_pages; i++) {
3633 page = extent_buffer_page(eb, i);
3635 ClearPageUptodate(page);
3640 int set_extent_buffer_uptodate(struct extent_io_tree *tree,
3641 struct extent_buffer *eb)
3645 unsigned long num_pages;
3647 num_pages = num_extent_pages(eb->start, eb->len);
3649 if (eb_straddles_pages(eb)) {
3650 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3653 for (i = 0; i < num_pages; i++) {
3654 page = extent_buffer_page(eb, i);
3655 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
3656 ((i == num_pages - 1) &&
3657 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
3658 check_page_uptodate(tree, page);
3661 SetPageUptodate(page);
3666 int extent_range_uptodate(struct extent_io_tree *tree,
3671 int pg_uptodate = 1;
3673 unsigned long index;
3675 if (__eb_straddles_pages(start, end - start + 1)) {
3676 ret = test_range_bit(tree, start, end,
3677 EXTENT_UPTODATE, 1, NULL);
3681 while (start <= end) {
3682 index = start >> PAGE_CACHE_SHIFT;
3683 page = find_get_page(tree->mapping, index);
3684 uptodate = PageUptodate(page);
3685 page_cache_release(page);
3690 start += PAGE_CACHE_SIZE;
3695 int extent_buffer_uptodate(struct extent_io_tree *tree,
3696 struct extent_buffer *eb,
3697 struct extent_state *cached_state)
3700 unsigned long num_pages;
3703 int pg_uptodate = 1;
3705 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3708 if (eb_straddles_pages(eb)) {
3709 ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3710 EXTENT_UPTODATE, 1, cached_state);
3715 num_pages = num_extent_pages(eb->start, eb->len);
3716 for (i = 0; i < num_pages; i++) {
3717 page = extent_buffer_page(eb, i);
3718 if (!PageUptodate(page)) {
3726 int read_extent_buffer_pages(struct extent_io_tree *tree,
3727 struct extent_buffer *eb,
3728 u64 start, int wait,
3729 get_extent_t *get_extent, int mirror_num)
3732 unsigned long start_i;
3736 int locked_pages = 0;
3737 int all_uptodate = 1;
3738 int inc_all_pages = 0;
3739 unsigned long num_pages;
3740 struct bio *bio = NULL;
3741 unsigned long bio_flags = 0;
3743 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3746 if (eb_straddles_pages(eb)) {
3747 if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3748 EXTENT_UPTODATE, 1, NULL)) {
3754 WARN_ON(start < eb->start);
3755 start_i = (start >> PAGE_CACHE_SHIFT) -
3756 (eb->start >> PAGE_CACHE_SHIFT);
3761 num_pages = num_extent_pages(eb->start, eb->len);
3762 for (i = start_i; i < num_pages; i++) {
3763 page = extent_buffer_page(eb, i);
3765 if (!trylock_page(page))
3771 if (!PageUptodate(page))
3776 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3780 for (i = start_i; i < num_pages; i++) {
3781 page = extent_buffer_page(eb, i);
3783 WARN_ON(!PagePrivate(page));
3785 set_page_extent_mapped(page);
3787 set_page_extent_head(page, eb->len);
3790 page_cache_get(page);
3791 if (!PageUptodate(page)) {
3794 ClearPageError(page);
3795 err = __extent_read_full_page(tree, page,
3797 mirror_num, &bio_flags);
3806 submit_one_bio(READ, bio, mirror_num, bio_flags);
3811 for (i = start_i; i < num_pages; i++) {
3812 page = extent_buffer_page(eb, i);
3813 wait_on_page_locked(page);
3814 if (!PageUptodate(page))
3819 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3824 while (locked_pages > 0) {
3825 page = extent_buffer_page(eb, i);
3833 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
3834 unsigned long start,
3841 char *dst = (char *)dstv;
3842 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3843 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3845 WARN_ON(start > eb->len);
3846 WARN_ON(start + len > eb->start + eb->len);
3848 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3851 page = extent_buffer_page(eb, i);
3853 cur = min(len, (PAGE_CACHE_SIZE - offset));
3854 kaddr = page_address(page);
3855 memcpy(dst, kaddr + offset, cur);
3864 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
3865 unsigned long min_len, char **map,
3866 unsigned long *map_start,
3867 unsigned long *map_len)
3869 size_t offset = start & (PAGE_CACHE_SIZE - 1);
3872 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3873 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3874 unsigned long end_i = (start_offset + start + min_len - 1) >>
3881 offset = start_offset;
3885 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
3888 if (start + min_len > eb->len) {
3889 printk(KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
3890 "wanted %lu %lu\n", (unsigned long long)eb->start,
3891 eb->len, start, min_len);
3896 p = extent_buffer_page(eb, i);
3897 kaddr = page_address(p);
3898 *map = kaddr + offset;
3899 *map_len = PAGE_CACHE_SIZE - offset;
3903 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
3904 unsigned long start,
3911 char *ptr = (char *)ptrv;
3912 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3913 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3916 WARN_ON(start > eb->len);
3917 WARN_ON(start + len > eb->start + eb->len);
3919 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3922 page = extent_buffer_page(eb, i);
3924 cur = min(len, (PAGE_CACHE_SIZE - offset));
3926 kaddr = page_address(page);
3927 ret = memcmp(ptr, kaddr + offset, cur);
3939 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
3940 unsigned long start, unsigned long len)
3946 char *src = (char *)srcv;
3947 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3948 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3950 WARN_ON(start > eb->len);
3951 WARN_ON(start + len > eb->start + eb->len);
3953 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3956 page = extent_buffer_page(eb, i);
3957 WARN_ON(!PageUptodate(page));
3959 cur = min(len, PAGE_CACHE_SIZE - offset);
3960 kaddr = page_address(page);
3961 memcpy(kaddr + offset, src, cur);
3970 void memset_extent_buffer(struct extent_buffer *eb, char c,
3971 unsigned long start, unsigned long len)
3977 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
3978 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
3980 WARN_ON(start > eb->len);
3981 WARN_ON(start + len > eb->start + eb->len);
3983 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
3986 page = extent_buffer_page(eb, i);
3987 WARN_ON(!PageUptodate(page));
3989 cur = min(len, PAGE_CACHE_SIZE - offset);
3990 kaddr = page_address(page);
3991 memset(kaddr + offset, c, cur);
3999 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
4000 unsigned long dst_offset, unsigned long src_offset,
4003 u64 dst_len = dst->len;
4008 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4009 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4011 WARN_ON(src->len != dst_len);
4013 offset = (start_offset + dst_offset) &
4014 ((unsigned long)PAGE_CACHE_SIZE - 1);
4017 page = extent_buffer_page(dst, i);
4018 WARN_ON(!PageUptodate(page));
4020 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
4022 kaddr = page_address(page);
4023 read_extent_buffer(src, kaddr + offset, src_offset, cur);
4032 static void move_pages(struct page *dst_page, struct page *src_page,
4033 unsigned long dst_off, unsigned long src_off,
4036 char *dst_kaddr = page_address(dst_page);
4037 if (dst_page == src_page) {
4038 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
4040 char *src_kaddr = page_address(src_page);
4041 char *p = dst_kaddr + dst_off + len;
4042 char *s = src_kaddr + src_off + len;
4049 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
4051 unsigned long distance = (src > dst) ? src - dst : dst - src;
4052 return distance < len;
4055 static void copy_pages(struct page *dst_page, struct page *src_page,
4056 unsigned long dst_off, unsigned long src_off,
4059 char *dst_kaddr = page_address(dst_page);
4062 if (dst_page != src_page) {
4063 src_kaddr = page_address(src_page);
4065 src_kaddr = dst_kaddr;
4066 BUG_ON(areas_overlap(src_off, dst_off, len));
4069 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
4072 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
4073 unsigned long src_offset, unsigned long len)
4076 size_t dst_off_in_page;
4077 size_t src_off_in_page;
4078 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4079 unsigned long dst_i;
4080 unsigned long src_i;
4082 if (src_offset + len > dst->len) {
4083 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4084 "len %lu dst len %lu\n", src_offset, len, dst->len);
4087 if (dst_offset + len > dst->len) {
4088 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4089 "len %lu dst len %lu\n", dst_offset, len, dst->len);
4094 dst_off_in_page = (start_offset + dst_offset) &
4095 ((unsigned long)PAGE_CACHE_SIZE - 1);
4096 src_off_in_page = (start_offset + src_offset) &
4097 ((unsigned long)PAGE_CACHE_SIZE - 1);
4099 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4100 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
4102 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
4104 cur = min_t(unsigned long, cur,
4105 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
4107 copy_pages(extent_buffer_page(dst, dst_i),
4108 extent_buffer_page(dst, src_i),
4109 dst_off_in_page, src_off_in_page, cur);
4117 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
4118 unsigned long src_offset, unsigned long len)
4121 size_t dst_off_in_page;
4122 size_t src_off_in_page;
4123 unsigned long dst_end = dst_offset + len - 1;
4124 unsigned long src_end = src_offset + len - 1;
4125 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4126 unsigned long dst_i;
4127 unsigned long src_i;
4129 if (src_offset + len > dst->len) {
4130 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4131 "len %lu len %lu\n", src_offset, len, dst->len);
4134 if (dst_offset + len > dst->len) {
4135 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4136 "len %lu len %lu\n", dst_offset, len, dst->len);
4139 if (!areas_overlap(src_offset, dst_offset, len)) {
4140 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
4144 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
4145 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
4147 dst_off_in_page = (start_offset + dst_end) &
4148 ((unsigned long)PAGE_CACHE_SIZE - 1);
4149 src_off_in_page = (start_offset + src_end) &
4150 ((unsigned long)PAGE_CACHE_SIZE - 1);
4152 cur = min_t(unsigned long, len, src_off_in_page + 1);
4153 cur = min(cur, dst_off_in_page + 1);
4154 move_pages(extent_buffer_page(dst, dst_i),
4155 extent_buffer_page(dst, src_i),
4156 dst_off_in_page - cur + 1,
4157 src_off_in_page - cur + 1, cur);
4165 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
4167 struct extent_buffer *eb =
4168 container_of(head, struct extent_buffer, rcu_head);
4170 btrfs_release_extent_buffer(eb);
4173 int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
4175 u64 start = page_offset(page);
4176 struct extent_buffer *eb;
4179 spin_lock(&tree->buffer_lock);
4180 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4182 spin_unlock(&tree->buffer_lock);
4186 if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
4192 * set @eb->refs to 0 if it is already 1, and then release the @eb.
4195 if (atomic_cmpxchg(&eb->refs, 1, 0) != 1) {
4200 radix_tree_delete(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4202 spin_unlock(&tree->buffer_lock);
4204 /* at this point we can safely release the extent buffer */
4205 if (atomic_read(&eb->refs) == 0)
4206 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);