1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/module.h>
8 #include <linux/spinlock.h>
9 #include <linux/blkdev.h>
10 #include <linux/swap.h>
11 #include <linux/writeback.h>
12 #include <linux/pagevec.h>
13 #include <linux/prefetch.h>
14 #include <linux/cleancache.h>
15 #include "extent_io.h"
16 #include "extent_map.h"
19 #include "btrfs_inode.h"
21 #include "check-integrity.h"
23 #include "rcu-string.h"
25 static struct kmem_cache *extent_state_cache;
26 static struct kmem_cache *extent_buffer_cache;
28 static LIST_HEAD(buffers);
29 static LIST_HEAD(states);
33 static DEFINE_SPINLOCK(leak_lock);
36 #define BUFFER_LRU_MAX 64
41 struct rb_node rb_node;
44 struct extent_page_data {
46 struct extent_io_tree *tree;
47 get_extent_t *get_extent;
48 unsigned long bio_flags;
50 /* tells writepage not to lock the state bits for this range
51 * it still does the unlocking
53 unsigned int extent_locked:1;
55 /* tells the submit_bio code to use a WRITE_SYNC */
56 unsigned int sync_io:1;
59 static noinline void flush_write_bio(void *data);
60 static inline struct btrfs_fs_info *
61 tree_fs_info(struct extent_io_tree *tree)
63 return btrfs_sb(tree->mapping->host->i_sb);
66 int __init extent_io_init(void)
68 extent_state_cache = kmem_cache_create("btrfs_extent_state",
69 sizeof(struct extent_state), 0,
70 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
71 if (!extent_state_cache)
74 extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
75 sizeof(struct extent_buffer), 0,
76 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
77 if (!extent_buffer_cache)
78 goto free_state_cache;
82 kmem_cache_destroy(extent_state_cache);
86 void extent_io_exit(void)
88 struct extent_state *state;
89 struct extent_buffer *eb;
91 while (!list_empty(&states)) {
92 state = list_entry(states.next, struct extent_state, leak_list);
93 printk(KERN_ERR "btrfs state leak: start %llu end %llu "
94 "state %lu in tree %p refs %d\n",
95 (unsigned long long)state->start,
96 (unsigned long long)state->end,
97 state->state, state->tree, atomic_read(&state->refs));
98 list_del(&state->leak_list);
99 kmem_cache_free(extent_state_cache, state);
103 while (!list_empty(&buffers)) {
104 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
105 printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
106 "refs %d\n", (unsigned long long)eb->start,
107 eb->len, atomic_read(&eb->refs));
108 list_del(&eb->leak_list);
109 kmem_cache_free(extent_buffer_cache, eb);
113 * Make sure all delayed rcu free are flushed before we
117 if (extent_state_cache)
118 kmem_cache_destroy(extent_state_cache);
119 if (extent_buffer_cache)
120 kmem_cache_destroy(extent_buffer_cache);
123 void extent_io_tree_init(struct extent_io_tree *tree,
124 struct address_space *mapping)
126 tree->state = RB_ROOT;
127 INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
129 tree->dirty_bytes = 0;
130 spin_lock_init(&tree->lock);
131 spin_lock_init(&tree->buffer_lock);
132 tree->mapping = mapping;
135 static struct extent_state *alloc_extent_state(gfp_t mask)
137 struct extent_state *state;
142 state = kmem_cache_alloc(extent_state_cache, mask);
149 spin_lock_irqsave(&leak_lock, flags);
150 list_add(&state->leak_list, &states);
151 spin_unlock_irqrestore(&leak_lock, flags);
153 atomic_set(&state->refs, 1);
154 init_waitqueue_head(&state->wq);
155 trace_alloc_extent_state(state, mask, _RET_IP_);
159 void free_extent_state(struct extent_state *state)
163 if (atomic_dec_and_test(&state->refs)) {
167 WARN_ON(state->tree);
169 spin_lock_irqsave(&leak_lock, flags);
170 list_del(&state->leak_list);
171 spin_unlock_irqrestore(&leak_lock, flags);
173 trace_free_extent_state(state, _RET_IP_);
174 kmem_cache_free(extent_state_cache, state);
178 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
179 struct rb_node *node)
181 struct rb_node **p = &root->rb_node;
182 struct rb_node *parent = NULL;
183 struct tree_entry *entry;
187 entry = rb_entry(parent, struct tree_entry, rb_node);
189 if (offset < entry->start)
191 else if (offset > entry->end)
197 rb_link_node(node, parent, p);
198 rb_insert_color(node, root);
202 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
203 struct rb_node **prev_ret,
204 struct rb_node **next_ret)
206 struct rb_root *root = &tree->state;
207 struct rb_node *n = root->rb_node;
208 struct rb_node *prev = NULL;
209 struct rb_node *orig_prev = NULL;
210 struct tree_entry *entry;
211 struct tree_entry *prev_entry = NULL;
214 entry = rb_entry(n, struct tree_entry, rb_node);
218 if (offset < entry->start)
220 else if (offset > entry->end)
228 while (prev && offset > prev_entry->end) {
229 prev = rb_next(prev);
230 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
237 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
238 while (prev && offset < prev_entry->start) {
239 prev = rb_prev(prev);
240 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
247 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
250 struct rb_node *prev = NULL;
253 ret = __etree_search(tree, offset, &prev, NULL);
259 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
260 struct extent_state *other)
262 if (tree->ops && tree->ops->merge_extent_hook)
263 tree->ops->merge_extent_hook(tree->mapping->host, new,
268 * utility function to look for merge candidates inside a given range.
269 * Any extents with matching state are merged together into a single
270 * extent in the tree. Extents with EXTENT_IO in their state field
271 * are not merged because the end_io handlers need to be able to do
272 * operations on them without sleeping (or doing allocations/splits).
274 * This should be called with the tree lock held.
276 static void merge_state(struct extent_io_tree *tree,
277 struct extent_state *state)
279 struct extent_state *other;
280 struct rb_node *other_node;
282 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
285 other_node = rb_prev(&state->rb_node);
287 other = rb_entry(other_node, struct extent_state, rb_node);
288 if (other->end == state->start - 1 &&
289 other->state == state->state) {
290 merge_cb(tree, state, other);
291 state->start = other->start;
293 rb_erase(&other->rb_node, &tree->state);
294 free_extent_state(other);
297 other_node = rb_next(&state->rb_node);
299 other = rb_entry(other_node, struct extent_state, rb_node);
300 if (other->start == state->end + 1 &&
301 other->state == state->state) {
302 merge_cb(tree, state, other);
303 state->end = other->end;
305 rb_erase(&other->rb_node, &tree->state);
306 free_extent_state(other);
311 static void set_state_cb(struct extent_io_tree *tree,
312 struct extent_state *state, int *bits)
314 if (tree->ops && tree->ops->set_bit_hook)
315 tree->ops->set_bit_hook(tree->mapping->host, state, bits);
318 static void clear_state_cb(struct extent_io_tree *tree,
319 struct extent_state *state, int *bits)
321 if (tree->ops && tree->ops->clear_bit_hook)
322 tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
325 static void set_state_bits(struct extent_io_tree *tree,
326 struct extent_state *state, int *bits);
329 * insert an extent_state struct into the tree. 'bits' are set on the
330 * struct before it is inserted.
332 * This may return -EEXIST if the extent is already there, in which case the
333 * state struct is freed.
335 * The tree lock is not taken internally. This is a utility function and
336 * probably isn't what you want to call (see set/clear_extent_bit).
338 static int insert_state(struct extent_io_tree *tree,
339 struct extent_state *state, u64 start, u64 end,
342 struct rb_node *node;
345 printk(KERN_ERR "btrfs end < start %llu %llu\n",
346 (unsigned long long)end,
347 (unsigned long long)start);
350 state->start = start;
353 set_state_bits(tree, state, bits);
355 node = tree_insert(&tree->state, end, &state->rb_node);
357 struct extent_state *found;
358 found = rb_entry(node, struct extent_state, rb_node);
359 printk(KERN_ERR "btrfs found node %llu %llu on insert of "
360 "%llu %llu\n", (unsigned long long)found->start,
361 (unsigned long long)found->end,
362 (unsigned long long)start, (unsigned long long)end);
366 merge_state(tree, state);
370 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
373 if (tree->ops && tree->ops->split_extent_hook)
374 tree->ops->split_extent_hook(tree->mapping->host, orig, split);
378 * split a given extent state struct in two, inserting the preallocated
379 * struct 'prealloc' as the newly created second half. 'split' indicates an
380 * offset inside 'orig' where it should be split.
383 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
384 * are two extent state structs in the tree:
385 * prealloc: [orig->start, split - 1]
386 * orig: [ split, orig->end ]
388 * The tree locks are not taken by this function. They need to be held
391 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
392 struct extent_state *prealloc, u64 split)
394 struct rb_node *node;
396 split_cb(tree, orig, split);
398 prealloc->start = orig->start;
399 prealloc->end = split - 1;
400 prealloc->state = orig->state;
403 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
405 free_extent_state(prealloc);
408 prealloc->tree = tree;
412 static struct extent_state *next_state(struct extent_state *state)
414 struct rb_node *next = rb_next(&state->rb_node);
416 return rb_entry(next, struct extent_state, rb_node);
422 * utility function to clear some bits in an extent state struct.
423 * it will optionally wake up any one waiting on this state (wake == 1).
425 * If no bits are set on the state struct after clearing things, the
426 * struct is freed and removed from the tree
428 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
429 struct extent_state *state,
432 struct extent_state *next;
433 int bits_to_clear = *bits & ~EXTENT_CTLBITS;
435 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
436 u64 range = state->end - state->start + 1;
437 WARN_ON(range > tree->dirty_bytes);
438 tree->dirty_bytes -= range;
440 clear_state_cb(tree, state, bits);
441 state->state &= ~bits_to_clear;
444 if (state->state == 0) {
445 next = next_state(state);
447 rb_erase(&state->rb_node, &tree->state);
449 free_extent_state(state);
454 merge_state(tree, state);
455 next = next_state(state);
460 static struct extent_state *
461 alloc_extent_state_atomic(struct extent_state *prealloc)
464 prealloc = alloc_extent_state(GFP_ATOMIC);
469 void extent_io_tree_panic(struct extent_io_tree *tree, int err)
471 btrfs_panic(tree_fs_info(tree), err, "Locking error: "
472 "Extent tree was modified by another "
473 "thread while locked.");
477 * clear some bits on a range in the tree. This may require splitting
478 * or inserting elements in the tree, so the gfp mask is used to
479 * indicate which allocations or sleeping are allowed.
481 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
482 * the given range from the tree regardless of state (ie for truncate).
484 * the range [start, end] is inclusive.
486 * This takes the tree lock, and returns 0 on success and < 0 on error.
488 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
489 int bits, int wake, int delete,
490 struct extent_state **cached_state,
493 struct extent_state *state;
494 struct extent_state *cached;
495 struct extent_state *prealloc = NULL;
496 struct rb_node *node;
502 bits |= ~EXTENT_CTLBITS;
503 bits |= EXTENT_FIRST_DELALLOC;
505 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
508 if (!prealloc && (mask & __GFP_WAIT)) {
509 prealloc = alloc_extent_state(mask);
514 spin_lock(&tree->lock);
516 cached = *cached_state;
519 *cached_state = NULL;
523 if (cached && cached->tree && cached->start <= start &&
524 cached->end > start) {
526 atomic_dec(&cached->refs);
531 free_extent_state(cached);
534 * this search will find the extents that end after
537 node = tree_search(tree, start);
540 state = rb_entry(node, struct extent_state, rb_node);
542 if (state->start > end)
544 WARN_ON(state->end < start);
545 last_end = state->end;
547 /* the state doesn't have the wanted bits, go ahead */
548 if (!(state->state & bits)) {
549 state = next_state(state);
554 * | ---- desired range ---- |
556 * | ------------- state -------------- |
558 * We need to split the extent we found, and may flip
559 * bits on second half.
561 * If the extent we found extends past our range, we
562 * just split and search again. It'll get split again
563 * the next time though.
565 * If the extent we found is inside our range, we clear
566 * the desired bit on it.
569 if (state->start < start) {
570 prealloc = alloc_extent_state_atomic(prealloc);
572 err = split_state(tree, state, prealloc, start);
574 extent_io_tree_panic(tree, err);
579 if (state->end <= end) {
580 state = clear_state_bit(tree, state, &bits, wake);
586 * | ---- desired range ---- |
588 * We need to split the extent, and clear the bit
591 if (state->start <= end && state->end > end) {
592 prealloc = alloc_extent_state_atomic(prealloc);
594 err = split_state(tree, state, prealloc, end + 1);
596 extent_io_tree_panic(tree, err);
601 clear_state_bit(tree, prealloc, &bits, wake);
607 state = clear_state_bit(tree, state, &bits, wake);
609 if (last_end == (u64)-1)
611 start = last_end + 1;
612 if (start <= end && state && !need_resched())
617 spin_unlock(&tree->lock);
619 free_extent_state(prealloc);
626 spin_unlock(&tree->lock);
627 if (mask & __GFP_WAIT)
632 static void wait_on_state(struct extent_io_tree *tree,
633 struct extent_state *state)
634 __releases(tree->lock)
635 __acquires(tree->lock)
638 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
639 spin_unlock(&tree->lock);
641 spin_lock(&tree->lock);
642 finish_wait(&state->wq, &wait);
646 * waits for one or more bits to clear on a range in the state tree.
647 * The range [start, end] is inclusive.
648 * The tree lock is taken by this function
650 void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
652 struct extent_state *state;
653 struct rb_node *node;
655 spin_lock(&tree->lock);
659 * this search will find all the extents that end after
662 node = tree_search(tree, start);
666 state = rb_entry(node, struct extent_state, rb_node);
668 if (state->start > end)
671 if (state->state & bits) {
672 start = state->start;
673 atomic_inc(&state->refs);
674 wait_on_state(tree, state);
675 free_extent_state(state);
678 start = state->end + 1;
683 cond_resched_lock(&tree->lock);
686 spin_unlock(&tree->lock);
689 static void set_state_bits(struct extent_io_tree *tree,
690 struct extent_state *state,
693 int bits_to_set = *bits & ~EXTENT_CTLBITS;
695 set_state_cb(tree, state, bits);
696 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
697 u64 range = state->end - state->start + 1;
698 tree->dirty_bytes += range;
700 state->state |= bits_to_set;
703 static void cache_state(struct extent_state *state,
704 struct extent_state **cached_ptr)
706 if (cached_ptr && !(*cached_ptr)) {
707 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
709 atomic_inc(&state->refs);
714 static void uncache_state(struct extent_state **cached_ptr)
716 if (cached_ptr && (*cached_ptr)) {
717 struct extent_state *state = *cached_ptr;
719 free_extent_state(state);
724 * set some bits on a range in the tree. This may require allocations or
725 * sleeping, so the gfp mask is used to indicate what is allowed.
727 * If any of the exclusive bits are set, this will fail with -EEXIST if some
728 * part of the range already has the desired bits set. The start of the
729 * existing range is returned in failed_start in this case.
731 * [start, end] is inclusive This takes the tree lock.
734 static int __must_check
735 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
736 int bits, int exclusive_bits, u64 *failed_start,
737 struct extent_state **cached_state, gfp_t mask)
739 struct extent_state *state;
740 struct extent_state *prealloc = NULL;
741 struct rb_node *node;
746 bits |= EXTENT_FIRST_DELALLOC;
748 if (!prealloc && (mask & __GFP_WAIT)) {
749 prealloc = alloc_extent_state(mask);
753 spin_lock(&tree->lock);
754 if (cached_state && *cached_state) {
755 state = *cached_state;
756 if (state->start <= start && state->end > start &&
758 node = &state->rb_node;
763 * this search will find all the extents that end after
766 node = tree_search(tree, start);
768 prealloc = alloc_extent_state_atomic(prealloc);
770 err = insert_state(tree, prealloc, start, end, &bits);
772 extent_io_tree_panic(tree, err);
777 state = rb_entry(node, struct extent_state, rb_node);
779 last_start = state->start;
780 last_end = state->end;
783 * | ---- desired range ---- |
786 * Just lock what we found and keep going
788 if (state->start == start && state->end <= end) {
789 if (state->state & exclusive_bits) {
790 *failed_start = state->start;
795 set_state_bits(tree, state, &bits);
796 cache_state(state, cached_state);
797 merge_state(tree, state);
798 if (last_end == (u64)-1)
800 start = last_end + 1;
801 state = next_state(state);
802 if (start < end && state && state->start == start &&
809 * | ---- desired range ---- |
812 * | ------------- state -------------- |
814 * We need to split the extent we found, and may flip bits on
817 * If the extent we found extends past our
818 * range, we just split and search again. It'll get split
819 * again the next time though.
821 * If the extent we found is inside our range, we set the
824 if (state->start < start) {
825 if (state->state & exclusive_bits) {
826 *failed_start = start;
831 prealloc = alloc_extent_state_atomic(prealloc);
833 err = split_state(tree, state, prealloc, start);
835 extent_io_tree_panic(tree, err);
840 if (state->end <= end) {
841 set_state_bits(tree, state, &bits);
842 cache_state(state, cached_state);
843 merge_state(tree, state);
844 if (last_end == (u64)-1)
846 start = last_end + 1;
847 state = next_state(state);
848 if (start < end && state && state->start == start &&
855 * | ---- desired range ---- |
856 * | state | or | state |
858 * There's a hole, we need to insert something in it and
859 * ignore the extent we found.
861 if (state->start > start) {
863 if (end < last_start)
866 this_end = last_start - 1;
868 prealloc = alloc_extent_state_atomic(prealloc);
872 * Avoid to free 'prealloc' if it can be merged with
875 err = insert_state(tree, prealloc, start, this_end,
878 extent_io_tree_panic(tree, err);
880 cache_state(prealloc, cached_state);
882 start = this_end + 1;
886 * | ---- desired range ---- |
888 * We need to split the extent, and set the bit
891 if (state->start <= end && state->end > end) {
892 if (state->state & exclusive_bits) {
893 *failed_start = start;
898 prealloc = alloc_extent_state_atomic(prealloc);
900 err = split_state(tree, state, prealloc, end + 1);
902 extent_io_tree_panic(tree, err);
904 set_state_bits(tree, prealloc, &bits);
905 cache_state(prealloc, cached_state);
906 merge_state(tree, prealloc);
914 spin_unlock(&tree->lock);
916 free_extent_state(prealloc);
923 spin_unlock(&tree->lock);
924 if (mask & __GFP_WAIT)
929 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits,
930 u64 *failed_start, struct extent_state **cached_state,
933 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
939 * convert_extent_bit - convert all bits in a given range from one bit to
941 * @tree: the io tree to search
942 * @start: the start offset in bytes
943 * @end: the end offset in bytes (inclusive)
944 * @bits: the bits to set in this range
945 * @clear_bits: the bits to clear in this range
946 * @cached_state: state that we're going to cache
947 * @mask: the allocation mask
949 * This will go through and set bits for the given range. If any states exist
950 * already in this range they are set with the given bit and cleared of the
951 * clear_bits. This is only meant to be used by things that are mergeable, ie
952 * converting from say DELALLOC to DIRTY. This is not meant to be used with
953 * boundary bits like LOCK.
955 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
956 int bits, int clear_bits,
957 struct extent_state **cached_state, gfp_t mask)
959 struct extent_state *state;
960 struct extent_state *prealloc = NULL;
961 struct rb_node *node;
967 if (!prealloc && (mask & __GFP_WAIT)) {
968 prealloc = alloc_extent_state(mask);
973 spin_lock(&tree->lock);
974 if (cached_state && *cached_state) {
975 state = *cached_state;
976 if (state->start <= start && state->end > start &&
978 node = &state->rb_node;
984 * this search will find all the extents that end after
987 node = tree_search(tree, start);
989 prealloc = alloc_extent_state_atomic(prealloc);
994 err = insert_state(tree, prealloc, start, end, &bits);
997 extent_io_tree_panic(tree, err);
1000 state = rb_entry(node, struct extent_state, rb_node);
1002 last_start = state->start;
1003 last_end = state->end;
1006 * | ---- desired range ---- |
1009 * Just lock what we found and keep going
1011 if (state->start == start && state->end <= end) {
1012 set_state_bits(tree, state, &bits);
1013 cache_state(state, cached_state);
1014 state = clear_state_bit(tree, state, &clear_bits, 0);
1015 if (last_end == (u64)-1)
1017 start = last_end + 1;
1018 if (start < end && state && state->start == start &&
1025 * | ---- desired range ---- |
1028 * | ------------- state -------------- |
1030 * We need to split the extent we found, and may flip bits on
1033 * If the extent we found extends past our
1034 * range, we just split and search again. It'll get split
1035 * again the next time though.
1037 * If the extent we found is inside our range, we set the
1038 * desired bit on it.
1040 if (state->start < start) {
1041 prealloc = alloc_extent_state_atomic(prealloc);
1046 err = split_state(tree, state, prealloc, start);
1048 extent_io_tree_panic(tree, err);
1052 if (state->end <= end) {
1053 set_state_bits(tree, state, &bits);
1054 cache_state(state, cached_state);
1055 state = clear_state_bit(tree, state, &clear_bits, 0);
1056 if (last_end == (u64)-1)
1058 start = last_end + 1;
1059 if (start < end && state && state->start == start &&
1066 * | ---- desired range ---- |
1067 * | state | or | state |
1069 * There's a hole, we need to insert something in it and
1070 * ignore the extent we found.
1072 if (state->start > start) {
1074 if (end < last_start)
1077 this_end = last_start - 1;
1079 prealloc = alloc_extent_state_atomic(prealloc);
1086 * Avoid to free 'prealloc' if it can be merged with
1089 err = insert_state(tree, prealloc, start, this_end,
1092 extent_io_tree_panic(tree, err);
1093 cache_state(prealloc, cached_state);
1095 start = this_end + 1;
1099 * | ---- desired range ---- |
1101 * We need to split the extent, and set the bit
1104 if (state->start <= end && state->end > end) {
1105 prealloc = alloc_extent_state_atomic(prealloc);
1111 err = split_state(tree, state, prealloc, end + 1);
1113 extent_io_tree_panic(tree, err);
1115 set_state_bits(tree, prealloc, &bits);
1116 cache_state(prealloc, cached_state);
1117 clear_state_bit(tree, prealloc, &clear_bits, 0);
1125 spin_unlock(&tree->lock);
1127 free_extent_state(prealloc);
1134 spin_unlock(&tree->lock);
1135 if (mask & __GFP_WAIT)
1140 /* wrappers around set/clear extent bit */
1141 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1144 return set_extent_bit(tree, start, end, EXTENT_DIRTY, NULL,
1148 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1149 int bits, gfp_t mask)
1151 return set_extent_bit(tree, start, end, bits, NULL,
1155 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1156 int bits, gfp_t mask)
1158 return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
1161 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
1162 struct extent_state **cached_state, gfp_t mask)
1164 return set_extent_bit(tree, start, end,
1165 EXTENT_DELALLOC | EXTENT_UPTODATE,
1166 NULL, cached_state, mask);
1169 int set_extent_defrag(struct extent_io_tree *tree, u64 start, u64 end,
1170 struct extent_state **cached_state, gfp_t mask)
1172 return set_extent_bit(tree, start, end,
1173 EXTENT_DELALLOC | EXTENT_UPTODATE | EXTENT_DEFRAG,
1174 NULL, cached_state, mask);
1177 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1180 return clear_extent_bit(tree, start, end,
1181 EXTENT_DIRTY | EXTENT_DELALLOC |
1182 EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
1185 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
1188 return set_extent_bit(tree, start, end, EXTENT_NEW, NULL,
1192 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
1193 struct extent_state **cached_state, gfp_t mask)
1195 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0,
1196 cached_state, mask);
1199 int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
1200 struct extent_state **cached_state, gfp_t mask)
1202 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
1203 cached_state, mask);
1207 * either insert or lock state struct between start and end use mask to tell
1208 * us if waiting is desired.
1210 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1211 int bits, struct extent_state **cached_state)
1216 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
1217 EXTENT_LOCKED, &failed_start,
1218 cached_state, GFP_NOFS);
1219 if (err == -EEXIST) {
1220 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1221 start = failed_start;
1224 WARN_ON(start > end);
1229 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1231 return lock_extent_bits(tree, start, end, 0, NULL);
1234 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1239 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1240 &failed_start, NULL, GFP_NOFS);
1241 if (err == -EEXIST) {
1242 if (failed_start > start)
1243 clear_extent_bit(tree, start, failed_start - 1,
1244 EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS);
1250 int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
1251 struct extent_state **cached, gfp_t mask)
1253 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
1257 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1259 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
1264 * helper function to set both pages and extents in the tree writeback
1266 static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1268 unsigned long index = start >> PAGE_CACHE_SHIFT;
1269 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1272 while (index <= end_index) {
1273 page = find_get_page(tree->mapping, index);
1274 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1275 set_page_writeback(page);
1276 page_cache_release(page);
1282 /* find the first state struct with 'bits' set after 'start', and
1283 * return it. tree->lock must be held. NULL will returned if
1284 * nothing was found after 'start'
1286 struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
1287 u64 start, int bits)
1289 struct rb_node *node;
1290 struct extent_state *state;
1293 * this search will find all the extents that end after
1296 node = tree_search(tree, start);
1301 state = rb_entry(node, struct extent_state, rb_node);
1302 if (state->end >= start && (state->state & bits))
1305 node = rb_next(node);
1314 * find the first offset in the io tree with 'bits' set. zero is
1315 * returned if we find something, and *start_ret and *end_ret are
1316 * set to reflect the state struct that was found.
1318 * If nothing was found, 1 is returned. If found something, return 0.
1320 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1321 u64 *start_ret, u64 *end_ret, int bits,
1322 struct extent_state **cached_state)
1324 struct extent_state *state;
1328 spin_lock(&tree->lock);
1329 if (cached_state && *cached_state) {
1330 state = *cached_state;
1331 if (state->end == start - 1 && state->tree) {
1332 n = rb_next(&state->rb_node);
1334 state = rb_entry(n, struct extent_state,
1336 if (state->state & bits)
1340 free_extent_state(*cached_state);
1341 *cached_state = NULL;
1344 free_extent_state(*cached_state);
1345 *cached_state = NULL;
1348 state = find_first_extent_bit_state(tree, start, bits);
1351 cache_state(state, cached_state);
1352 *start_ret = state->start;
1353 *end_ret = state->end;
1357 spin_unlock(&tree->lock);
1362 * find a contiguous range of bytes in the file marked as delalloc, not
1363 * more than 'max_bytes'. start and end are used to return the range,
1365 * 1 is returned if we find something, 0 if nothing was in the tree
1367 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1368 u64 *start, u64 *end, u64 max_bytes,
1369 struct extent_state **cached_state)
1371 struct rb_node *node;
1372 struct extent_state *state;
1373 u64 cur_start = *start;
1375 u64 total_bytes = 0;
1377 spin_lock(&tree->lock);
1380 * this search will find all the extents that end after
1383 node = tree_search(tree, cur_start);
1391 state = rb_entry(node, struct extent_state, rb_node);
1392 if (found && (state->start != cur_start ||
1393 (state->state & EXTENT_BOUNDARY))) {
1396 if (!(state->state & EXTENT_DELALLOC)) {
1402 *start = state->start;
1403 *cached_state = state;
1404 atomic_inc(&state->refs);
1408 cur_start = state->end + 1;
1409 node = rb_next(node);
1412 total_bytes += state->end - state->start + 1;
1413 if (total_bytes >= max_bytes)
1417 spin_unlock(&tree->lock);
1421 static noinline void __unlock_for_delalloc(struct inode *inode,
1422 struct page *locked_page,
1426 struct page *pages[16];
1427 unsigned long index = start >> PAGE_CACHE_SHIFT;
1428 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1429 unsigned long nr_pages = end_index - index + 1;
1432 if (index == locked_page->index && end_index == index)
1435 while (nr_pages > 0) {
1436 ret = find_get_pages_contig(inode->i_mapping, index,
1437 min_t(unsigned long, nr_pages,
1438 ARRAY_SIZE(pages)), pages);
1439 for (i = 0; i < ret; i++) {
1440 if (pages[i] != locked_page)
1441 unlock_page(pages[i]);
1442 page_cache_release(pages[i]);
1450 static noinline int lock_delalloc_pages(struct inode *inode,
1451 struct page *locked_page,
1455 unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
1456 unsigned long start_index = index;
1457 unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
1458 unsigned long pages_locked = 0;
1459 struct page *pages[16];
1460 unsigned long nrpages;
1464 /* the caller is responsible for locking the start index */
1465 if (index == locked_page->index && index == end_index)
1468 /* skip the page at the start index */
1469 nrpages = end_index - index + 1;
1470 while (nrpages > 0) {
1471 ret = find_get_pages_contig(inode->i_mapping, index,
1472 min_t(unsigned long,
1473 nrpages, ARRAY_SIZE(pages)), pages);
1478 /* now we have an array of pages, lock them all */
1479 for (i = 0; i < ret; i++) {
1481 * the caller is taking responsibility for
1484 if (pages[i] != locked_page) {
1485 lock_page(pages[i]);
1486 if (!PageDirty(pages[i]) ||
1487 pages[i]->mapping != inode->i_mapping) {
1489 unlock_page(pages[i]);
1490 page_cache_release(pages[i]);
1494 page_cache_release(pages[i]);
1503 if (ret && pages_locked) {
1504 __unlock_for_delalloc(inode, locked_page,
1506 ((u64)(start_index + pages_locked - 1)) <<
1513 * find a contiguous range of bytes in the file marked as delalloc, not
1514 * more than 'max_bytes'. start and end are used to return the range,
1516 * 1 is returned if we find something, 0 if nothing was in the tree
1518 static noinline u64 find_lock_delalloc_range(struct inode *inode,
1519 struct extent_io_tree *tree,
1520 struct page *locked_page,
1521 u64 *start, u64 *end,
1527 struct extent_state *cached_state = NULL;
1532 /* step one, find a bunch of delalloc bytes starting at start */
1533 delalloc_start = *start;
1535 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1536 max_bytes, &cached_state);
1537 if (!found || delalloc_end <= *start) {
1538 *start = delalloc_start;
1539 *end = delalloc_end;
1540 free_extent_state(cached_state);
1545 * start comes from the offset of locked_page. We have to lock
1546 * pages in order, so we can't process delalloc bytes before
1549 if (delalloc_start < *start)
1550 delalloc_start = *start;
1553 * make sure to limit the number of pages we try to lock down
1556 if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1557 delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
1559 /* step two, lock all the pages after the page that has start */
1560 ret = lock_delalloc_pages(inode, locked_page,
1561 delalloc_start, delalloc_end);
1562 if (ret == -EAGAIN) {
1563 /* some of the pages are gone, lets avoid looping by
1564 * shortening the size of the delalloc range we're searching
1566 free_extent_state(cached_state);
1568 unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
1569 max_bytes = PAGE_CACHE_SIZE - offset;
1577 BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
1579 /* step three, lock the state bits for the whole range */
1580 lock_extent_bits(tree, delalloc_start, delalloc_end, 0, &cached_state);
1582 /* then test to make sure it is all still delalloc */
1583 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1584 EXTENT_DELALLOC, 1, cached_state);
1586 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1587 &cached_state, GFP_NOFS);
1588 __unlock_for_delalloc(inode, locked_page,
1589 delalloc_start, delalloc_end);
1593 free_extent_state(cached_state);
1594 *start = delalloc_start;
1595 *end = delalloc_end;
1600 int extent_clear_unlock_delalloc(struct inode *inode,
1601 struct extent_io_tree *tree,
1602 u64 start, u64 end, struct page *locked_page,
1606 struct page *pages[16];
1607 unsigned long index = start >> PAGE_CACHE_SHIFT;
1608 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1609 unsigned long nr_pages = end_index - index + 1;
1613 if (op & EXTENT_CLEAR_UNLOCK)
1614 clear_bits |= EXTENT_LOCKED;
1615 if (op & EXTENT_CLEAR_DIRTY)
1616 clear_bits |= EXTENT_DIRTY;
1618 if (op & EXTENT_CLEAR_DELALLOC)
1619 clear_bits |= EXTENT_DELALLOC;
1621 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1622 if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
1623 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
1624 EXTENT_SET_PRIVATE2)))
1627 while (nr_pages > 0) {
1628 ret = find_get_pages_contig(inode->i_mapping, index,
1629 min_t(unsigned long,
1630 nr_pages, ARRAY_SIZE(pages)), pages);
1631 for (i = 0; i < ret; i++) {
1633 if (op & EXTENT_SET_PRIVATE2)
1634 SetPagePrivate2(pages[i]);
1636 if (pages[i] == locked_page) {
1637 page_cache_release(pages[i]);
1640 if (op & EXTENT_CLEAR_DIRTY)
1641 clear_page_dirty_for_io(pages[i]);
1642 if (op & EXTENT_SET_WRITEBACK)
1643 set_page_writeback(pages[i]);
1644 if (op & EXTENT_END_WRITEBACK)
1645 end_page_writeback(pages[i]);
1646 if (op & EXTENT_CLEAR_UNLOCK_PAGE)
1647 unlock_page(pages[i]);
1648 page_cache_release(pages[i]);
1658 * count the number of bytes in the tree that have a given bit(s)
1659 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1660 * cached. The total number found is returned.
1662 u64 count_range_bits(struct extent_io_tree *tree,
1663 u64 *start, u64 search_end, u64 max_bytes,
1664 unsigned long bits, int contig)
1666 struct rb_node *node;
1667 struct extent_state *state;
1668 u64 cur_start = *start;
1669 u64 total_bytes = 0;
1673 if (search_end <= cur_start) {
1678 spin_lock(&tree->lock);
1679 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1680 total_bytes = tree->dirty_bytes;
1684 * this search will find all the extents that end after
1687 node = tree_search(tree, cur_start);
1692 state = rb_entry(node, struct extent_state, rb_node);
1693 if (state->start > search_end)
1695 if (contig && found && state->start > last + 1)
1697 if (state->end >= cur_start && (state->state & bits) == bits) {
1698 total_bytes += min(search_end, state->end) + 1 -
1699 max(cur_start, state->start);
1700 if (total_bytes >= max_bytes)
1703 *start = max(cur_start, state->start);
1707 } else if (contig && found) {
1710 node = rb_next(node);
1715 spin_unlock(&tree->lock);
1720 * set the private field for a given byte offset in the tree. If there isn't
1721 * an extent_state there already, this does nothing.
1723 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1725 struct rb_node *node;
1726 struct extent_state *state;
1729 spin_lock(&tree->lock);
1731 * this search will find all the extents that end after
1734 node = tree_search(tree, start);
1739 state = rb_entry(node, struct extent_state, rb_node);
1740 if (state->start != start) {
1744 state->private = private;
1746 spin_unlock(&tree->lock);
1750 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1752 struct rb_node *node;
1753 struct extent_state *state;
1756 spin_lock(&tree->lock);
1758 * this search will find all the extents that end after
1761 node = tree_search(tree, start);
1766 state = rb_entry(node, struct extent_state, rb_node);
1767 if (state->start != start) {
1771 *private = state->private;
1773 spin_unlock(&tree->lock);
1778 * searches a range in the state tree for a given mask.
1779 * If 'filled' == 1, this returns 1 only if every extent in the tree
1780 * has the bits set. Otherwise, 1 is returned if any bit in the
1781 * range is found set.
1783 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1784 int bits, int filled, struct extent_state *cached)
1786 struct extent_state *state = NULL;
1787 struct rb_node *node;
1790 spin_lock(&tree->lock);
1791 if (cached && cached->tree && cached->start <= start &&
1792 cached->end > start)
1793 node = &cached->rb_node;
1795 node = tree_search(tree, start);
1796 while (node && start <= end) {
1797 state = rb_entry(node, struct extent_state, rb_node);
1799 if (filled && state->start > start) {
1804 if (state->start > end)
1807 if (state->state & bits) {
1811 } else if (filled) {
1816 if (state->end == (u64)-1)
1819 start = state->end + 1;
1822 node = rb_next(node);
1829 spin_unlock(&tree->lock);
1834 * helper function to set a given page up to date if all the
1835 * extents in the tree for that page are up to date
1837 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
1839 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1840 u64 end = start + PAGE_CACHE_SIZE - 1;
1841 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1842 SetPageUptodate(page);
1846 * helper function to unlock a page if all the extents in the tree
1847 * for that page are unlocked
1849 static void check_page_locked(struct extent_io_tree *tree, struct page *page)
1851 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1852 u64 end = start + PAGE_CACHE_SIZE - 1;
1853 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
1858 * helper function to end page writeback if all the extents
1859 * in the tree for that page are done with writeback
1861 static void check_page_writeback(struct extent_io_tree *tree,
1864 end_page_writeback(page);
1868 * When IO fails, either with EIO or csum verification fails, we
1869 * try other mirrors that might have a good copy of the data. This
1870 * io_failure_record is used to record state as we go through all the
1871 * mirrors. If another mirror has good data, the page is set up to date
1872 * and things continue. If a good mirror can't be found, the original
1873 * bio end_io callback is called to indicate things have failed.
1875 struct io_failure_record {
1880 unsigned long bio_flags;
1886 static int free_io_failure(struct inode *inode, struct io_failure_record *rec,
1891 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1893 set_state_private(failure_tree, rec->start, 0);
1894 ret = clear_extent_bits(failure_tree, rec->start,
1895 rec->start + rec->len - 1,
1896 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
1901 ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
1902 rec->start + rec->len - 1,
1903 EXTENT_DAMAGED, GFP_NOFS);
1912 static void repair_io_failure_callback(struct bio *bio, int err)
1914 complete(bio->bi_private);
1918 * this bypasses the standard btrfs submit functions deliberately, as
1919 * the standard behavior is to write all copies in a raid setup. here we only
1920 * want to write the one bad copy. so we do the mapping for ourselves and issue
1921 * submit_bio directly.
1922 * to avoid any synchonization issues, wait for the data after writing, which
1923 * actually prevents the read that triggered the error from finishing.
1924 * currently, there can be no more than two copies of every data bit. thus,
1925 * exactly one rewrite is required.
1927 int repair_io_failure(struct btrfs_mapping_tree *map_tree, u64 start,
1928 u64 length, u64 logical, struct page *page,
1932 struct btrfs_device *dev;
1933 DECLARE_COMPLETION_ONSTACK(compl);
1936 struct btrfs_bio *bbio = NULL;
1939 BUG_ON(!mirror_num);
1941 bio = bio_alloc(GFP_NOFS, 1);
1944 bio->bi_private = &compl;
1945 bio->bi_end_io = repair_io_failure_callback;
1947 map_length = length;
1949 ret = btrfs_map_block(map_tree, WRITE, logical,
1950 &map_length, &bbio, mirror_num);
1955 BUG_ON(mirror_num != bbio->mirror_num);
1956 sector = bbio->stripes[mirror_num-1].physical >> 9;
1957 bio->bi_sector = sector;
1958 dev = bbio->stripes[mirror_num-1].dev;
1960 if (!dev || !dev->bdev || !dev->writeable) {
1964 bio->bi_bdev = dev->bdev;
1965 bio_add_page(bio, page, length, start-page_offset(page));
1966 btrfsic_submit_bio(WRITE_SYNC, bio);
1967 wait_for_completion(&compl);
1969 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
1970 /* try to remap that extent elsewhere? */
1972 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
1976 printk_ratelimited_in_rcu(KERN_INFO "btrfs read error corrected: ino %lu off %llu "
1977 "(dev %s sector %llu)\n", page->mapping->host->i_ino,
1978 start, rcu_str_deref(dev->name), sector);
1984 int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb,
1987 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
1988 u64 start = eb->start;
1989 unsigned long i, num_pages = num_extent_pages(eb->start, eb->len);
1992 for (i = 0; i < num_pages; i++) {
1993 struct page *p = extent_buffer_page(eb, i);
1994 ret = repair_io_failure(map_tree, start, PAGE_CACHE_SIZE,
1995 start, p, mirror_num);
1998 start += PAGE_CACHE_SIZE;
2005 * each time an IO finishes, we do a fast check in the IO failure tree
2006 * to see if we need to process or clean up an io_failure_record
2008 static int clean_io_failure(u64 start, struct page *page)
2011 u64 private_failure;
2012 struct io_failure_record *failrec;
2013 struct btrfs_mapping_tree *map_tree;
2014 struct extent_state *state;
2018 struct inode *inode = page->mapping->host;
2021 ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
2022 (u64)-1, 1, EXTENT_DIRTY, 0);
2026 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree, start,
2031 failrec = (struct io_failure_record *)(unsigned long) private_failure;
2032 BUG_ON(!failrec->this_mirror);
2034 if (failrec->in_validation) {
2035 /* there was no real error, just free the record */
2036 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2042 spin_lock(&BTRFS_I(inode)->io_tree.lock);
2043 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
2046 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
2048 if (state && state->start == failrec->start) {
2049 map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree;
2050 num_copies = btrfs_num_copies(map_tree, failrec->logical,
2052 if (num_copies > 1) {
2053 ret = repair_io_failure(map_tree, start, failrec->len,
2054 failrec->logical, page,
2055 failrec->failed_mirror);
2062 ret = free_io_failure(inode, failrec, did_repair);
2068 * this is a generic handler for readpage errors (default
2069 * readpage_io_failed_hook). if other copies exist, read those and write back
2070 * good data to the failed position. does not investigate in remapping the
2071 * failed extent elsewhere, hoping the device will be smart enough to do this as
2075 static int bio_readpage_error(struct bio *failed_bio, struct page *page,
2076 u64 start, u64 end, int failed_mirror,
2077 struct extent_state *state)
2079 struct io_failure_record *failrec = NULL;
2081 struct extent_map *em;
2082 struct inode *inode = page->mapping->host;
2083 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2084 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2085 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2092 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
2094 ret = get_state_private(failure_tree, start, &private);
2096 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2099 failrec->start = start;
2100 failrec->len = end - start + 1;
2101 failrec->this_mirror = 0;
2102 failrec->bio_flags = 0;
2103 failrec->in_validation = 0;
2105 read_lock(&em_tree->lock);
2106 em = lookup_extent_mapping(em_tree, start, failrec->len);
2108 read_unlock(&em_tree->lock);
2113 if (em->start > start || em->start + em->len < start) {
2114 free_extent_map(em);
2117 read_unlock(&em_tree->lock);
2123 logical = start - em->start;
2124 logical = em->block_start + logical;
2125 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2126 logical = em->block_start;
2127 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2128 extent_set_compress_type(&failrec->bio_flags,
2131 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2132 "len=%llu\n", logical, start, failrec->len);
2133 failrec->logical = logical;
2134 free_extent_map(em);
2136 /* set the bits in the private failure tree */
2137 ret = set_extent_bits(failure_tree, start, end,
2138 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
2140 ret = set_state_private(failure_tree, start,
2141 (u64)(unsigned long)failrec);
2142 /* set the bits in the inode's tree */
2144 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED,
2151 failrec = (struct io_failure_record *)(unsigned long)private;
2152 pr_debug("bio_readpage_error: (found) logical=%llu, "
2153 "start=%llu, len=%llu, validation=%d\n",
2154 failrec->logical, failrec->start, failrec->len,
2155 failrec->in_validation);
2157 * when data can be on disk more than twice, add to failrec here
2158 * (e.g. with a list for failed_mirror) to make
2159 * clean_io_failure() clean all those errors at once.
2162 num_copies = btrfs_num_copies(
2163 &BTRFS_I(inode)->root->fs_info->mapping_tree,
2164 failrec->logical, failrec->len);
2165 if (num_copies == 1) {
2167 * we only have a single copy of the data, so don't bother with
2168 * all the retry and error correction code that follows. no
2169 * matter what the error is, it is very likely to persist.
2171 pr_debug("bio_readpage_error: cannot repair, num_copies == 1. "
2172 "state=%p, num_copies=%d, next_mirror %d, "
2173 "failed_mirror %d\n", state, num_copies,
2174 failrec->this_mirror, failed_mirror);
2175 free_io_failure(inode, failrec, 0);
2180 spin_lock(&tree->lock);
2181 state = find_first_extent_bit_state(tree, failrec->start,
2183 if (state && state->start != failrec->start)
2185 spin_unlock(&tree->lock);
2189 * there are two premises:
2190 * a) deliver good data to the caller
2191 * b) correct the bad sectors on disk
2193 if (failed_bio->bi_vcnt > 1) {
2195 * to fulfill b), we need to know the exact failing sectors, as
2196 * we don't want to rewrite any more than the failed ones. thus,
2197 * we need separate read requests for the failed bio
2199 * if the following BUG_ON triggers, our validation request got
2200 * merged. we need separate requests for our algorithm to work.
2202 BUG_ON(failrec->in_validation);
2203 failrec->in_validation = 1;
2204 failrec->this_mirror = failed_mirror;
2205 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
2208 * we're ready to fulfill a) and b) alongside. get a good copy
2209 * of the failed sector and if we succeed, we have setup
2210 * everything for repair_io_failure to do the rest for us.
2212 if (failrec->in_validation) {
2213 BUG_ON(failrec->this_mirror != failed_mirror);
2214 failrec->in_validation = 0;
2215 failrec->this_mirror = 0;
2217 failrec->failed_mirror = failed_mirror;
2218 failrec->this_mirror++;
2219 if (failrec->this_mirror == failed_mirror)
2220 failrec->this_mirror++;
2221 read_mode = READ_SYNC;
2224 if (!state || failrec->this_mirror > num_copies) {
2225 pr_debug("bio_readpage_error: (fail) state=%p, num_copies=%d, "
2226 "next_mirror %d, failed_mirror %d\n", state,
2227 num_copies, failrec->this_mirror, failed_mirror);
2228 free_io_failure(inode, failrec, 0);
2232 bio = bio_alloc(GFP_NOFS, 1);
2234 free_io_failure(inode, failrec, 0);
2237 bio->bi_private = state;
2238 bio->bi_end_io = failed_bio->bi_end_io;
2239 bio->bi_sector = failrec->logical >> 9;
2240 bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
2243 bio_add_page(bio, page, failrec->len, start - page_offset(page));
2245 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2246 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode,
2247 failrec->this_mirror, num_copies, failrec->in_validation);
2249 ret = tree->ops->submit_bio_hook(inode, read_mode, bio,
2250 failrec->this_mirror,
2251 failrec->bio_flags, 0);
2255 /* lots and lots of room for performance fixes in the end_bio funcs */
2257 int end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2259 int uptodate = (err == 0);
2260 struct extent_io_tree *tree;
2263 tree = &BTRFS_I(page->mapping->host)->io_tree;
2265 if (tree->ops && tree->ops->writepage_end_io_hook) {
2266 ret = tree->ops->writepage_end_io_hook(page, start,
2267 end, NULL, uptodate);
2273 ClearPageUptodate(page);
2280 * after a writepage IO is done, we need to:
2281 * clear the uptodate bits on error
2282 * clear the writeback bits in the extent tree for this IO
2283 * end_page_writeback if the page has no more pending IO
2285 * Scheduling is not allowed, so the extent state tree is expected
2286 * to have one and only one object corresponding to this IO.
2288 static void end_bio_extent_writepage(struct bio *bio, int err)
2290 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2291 struct extent_io_tree *tree;
2297 struct page *page = bvec->bv_page;
2298 tree = &BTRFS_I(page->mapping->host)->io_tree;
2300 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
2302 end = start + bvec->bv_len - 1;
2304 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
2309 if (--bvec >= bio->bi_io_vec)
2310 prefetchw(&bvec->bv_page->flags);
2312 if (end_extent_writepage(page, err, start, end))
2316 end_page_writeback(page);
2318 check_page_writeback(tree, page);
2319 } while (bvec >= bio->bi_io_vec);
2325 * after a readpage IO is done, we need to:
2326 * clear the uptodate bits on error
2327 * set the uptodate bits if things worked
2328 * set the page up to date if all extents in the tree are uptodate
2329 * clear the lock bit in the extent tree
2330 * unlock the page if there are no other extents locked for it
2332 * Scheduling is not allowed, so the extent state tree is expected
2333 * to have one and only one object corresponding to this IO.
2335 static void end_bio_extent_readpage(struct bio *bio, int err)
2337 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
2338 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
2339 struct bio_vec *bvec = bio->bi_io_vec;
2340 struct extent_io_tree *tree;
2351 struct page *page = bvec->bv_page;
2352 struct extent_state *cached = NULL;
2353 struct extent_state *state;
2355 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2356 "mirror=%ld\n", (u64)bio->bi_sector, err,
2357 (long int)bio->bi_bdev);
2358 tree = &BTRFS_I(page->mapping->host)->io_tree;
2360 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
2362 end = start + bvec->bv_len - 1;
2364 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
2369 if (++bvec <= bvec_end)
2370 prefetchw(&bvec->bv_page->flags);
2372 spin_lock(&tree->lock);
2373 state = find_first_extent_bit_state(tree, start, EXTENT_LOCKED);
2374 if (state && state->start == start) {
2376 * take a reference on the state, unlock will drop
2379 cache_state(state, &cached);
2381 spin_unlock(&tree->lock);
2383 mirror = (int)(unsigned long)bio->bi_bdev;
2384 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
2385 ret = tree->ops->readpage_end_io_hook(page, start, end,
2390 clean_io_failure(start, page);
2393 if (!uptodate && tree->ops && tree->ops->readpage_io_failed_hook) {
2394 ret = tree->ops->readpage_io_failed_hook(page, mirror);
2396 test_bit(BIO_UPTODATE, &bio->bi_flags))
2398 } else if (!uptodate) {
2400 * The generic bio_readpage_error handles errors the
2401 * following way: If possible, new read requests are
2402 * created and submitted and will end up in
2403 * end_bio_extent_readpage as well (if we're lucky, not
2404 * in the !uptodate case). In that case it returns 0 and
2405 * we just go on with the next page in our bio. If it
2406 * can't handle the error it will return -EIO and we
2407 * remain responsible for that page.
2409 ret = bio_readpage_error(bio, page, start, end, mirror, NULL);
2412 test_bit(BIO_UPTODATE, &bio->bi_flags);
2415 uncache_state(&cached);
2420 if (uptodate && tree->track_uptodate) {
2421 set_extent_uptodate(tree, start, end, &cached,
2424 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2428 SetPageUptodate(page);
2430 ClearPageUptodate(page);
2436 check_page_uptodate(tree, page);
2438 ClearPageUptodate(page);
2441 check_page_locked(tree, page);
2443 } while (bvec <= bvec_end);
2449 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2454 bio = bio_alloc(gfp_flags, nr_vecs);
2456 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2457 while (!bio && (nr_vecs /= 2))
2458 bio = bio_alloc(gfp_flags, nr_vecs);
2463 bio->bi_bdev = bdev;
2464 bio->bi_sector = first_sector;
2470 * Since writes are async, they will only return -ENOMEM.
2471 * Reads can return the full range of I/O error conditions.
2473 static int __must_check submit_one_bio(int rw, struct bio *bio,
2474 int mirror_num, unsigned long bio_flags)
2477 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2478 struct page *page = bvec->bv_page;
2479 struct extent_io_tree *tree = bio->bi_private;
2482 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
2484 bio->bi_private = NULL;
2488 if (tree->ops && tree->ops->submit_bio_hook)
2489 ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
2490 mirror_num, bio_flags, start);
2492 btrfsic_submit_bio(rw, bio);
2494 if (bio_flagged(bio, BIO_EOPNOTSUPP))
2500 static int merge_bio(struct extent_io_tree *tree, struct page *page,
2501 unsigned long offset, size_t size, struct bio *bio,
2502 unsigned long bio_flags)
2505 if (tree->ops && tree->ops->merge_bio_hook)
2506 ret = tree->ops->merge_bio_hook(page, offset, size, bio,
2513 static int submit_extent_page(int rw, struct extent_io_tree *tree,
2514 struct page *page, sector_t sector,
2515 size_t size, unsigned long offset,
2516 struct block_device *bdev,
2517 struct bio **bio_ret,
2518 unsigned long max_pages,
2519 bio_end_io_t end_io_func,
2521 unsigned long prev_bio_flags,
2522 unsigned long bio_flags)
2528 int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
2529 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2530 size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
2532 if (bio_ret && *bio_ret) {
2535 contig = bio->bi_sector == sector;
2537 contig = bio->bi_sector + (bio->bi_size >> 9) ==
2540 if (prev_bio_flags != bio_flags || !contig ||
2541 merge_bio(tree, page, offset, page_size, bio, bio_flags) ||
2542 bio_add_page(bio, page, page_size, offset) < page_size) {
2543 ret = submit_one_bio(rw, bio, mirror_num,
2552 if (this_compressed)
2555 nr = bio_get_nr_vecs(bdev);
2557 bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
2561 bio_add_page(bio, page, page_size, offset);
2562 bio->bi_end_io = end_io_func;
2563 bio->bi_private = tree;
2568 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
2573 void attach_extent_buffer_page(struct extent_buffer *eb, struct page *page)
2575 if (!PagePrivate(page)) {
2576 SetPagePrivate(page);
2577 page_cache_get(page);
2578 set_page_private(page, (unsigned long)eb);
2580 WARN_ON(page->private != (unsigned long)eb);
2584 void set_page_extent_mapped(struct page *page)
2586 if (!PagePrivate(page)) {
2587 SetPagePrivate(page);
2588 page_cache_get(page);
2589 set_page_private(page, EXTENT_PAGE_PRIVATE);
2594 * basic readpage implementation. Locked extent state structs are inserted
2595 * into the tree that are removed when the IO is done (by the end_io
2597 * XXX JDM: This needs looking at to ensure proper page locking
2599 static int __extent_read_full_page(struct extent_io_tree *tree,
2601 get_extent_t *get_extent,
2602 struct bio **bio, int mirror_num,
2603 unsigned long *bio_flags)
2605 struct inode *inode = page->mapping->host;
2606 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2607 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2611 u64 last_byte = i_size_read(inode);
2615 struct extent_map *em;
2616 struct block_device *bdev;
2617 struct btrfs_ordered_extent *ordered;
2620 size_t pg_offset = 0;
2622 size_t disk_io_size;
2623 size_t blocksize = inode->i_sb->s_blocksize;
2624 unsigned long this_bio_flag = 0;
2626 set_page_extent_mapped(page);
2628 if (!PageUptodate(page)) {
2629 if (cleancache_get_page(page) == 0) {
2630 BUG_ON(blocksize != PAGE_SIZE);
2637 lock_extent(tree, start, end);
2638 ordered = btrfs_lookup_ordered_extent(inode, start);
2641 unlock_extent(tree, start, end);
2642 btrfs_start_ordered_extent(inode, ordered, 1);
2643 btrfs_put_ordered_extent(ordered);
2646 if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
2648 size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
2651 iosize = PAGE_CACHE_SIZE - zero_offset;
2652 userpage = kmap_atomic(page);
2653 memset(userpage + zero_offset, 0, iosize);
2654 flush_dcache_page(page);
2655 kunmap_atomic(userpage);
2658 while (cur <= end) {
2659 if (cur >= last_byte) {
2661 struct extent_state *cached = NULL;
2663 iosize = PAGE_CACHE_SIZE - pg_offset;
2664 userpage = kmap_atomic(page);
2665 memset(userpage + pg_offset, 0, iosize);
2666 flush_dcache_page(page);
2667 kunmap_atomic(userpage);
2668 set_extent_uptodate(tree, cur, cur + iosize - 1,
2670 unlock_extent_cached(tree, cur, cur + iosize - 1,
2674 em = get_extent(inode, page, pg_offset, cur,
2676 if (IS_ERR_OR_NULL(em)) {
2678 unlock_extent(tree, cur, end);
2681 extent_offset = cur - em->start;
2682 BUG_ON(extent_map_end(em) <= cur);
2685 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2686 this_bio_flag = EXTENT_BIO_COMPRESSED;
2687 extent_set_compress_type(&this_bio_flag,
2691 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2692 cur_end = min(extent_map_end(em) - 1, end);
2693 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2694 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2695 disk_io_size = em->block_len;
2696 sector = em->block_start >> 9;
2698 sector = (em->block_start + extent_offset) >> 9;
2699 disk_io_size = iosize;
2702 block_start = em->block_start;
2703 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2704 block_start = EXTENT_MAP_HOLE;
2705 free_extent_map(em);
2708 /* we've found a hole, just zero and go on */
2709 if (block_start == EXTENT_MAP_HOLE) {
2711 struct extent_state *cached = NULL;
2713 userpage = kmap_atomic(page);
2714 memset(userpage + pg_offset, 0, iosize);
2715 flush_dcache_page(page);
2716 kunmap_atomic(userpage);
2718 set_extent_uptodate(tree, cur, cur + iosize - 1,
2720 unlock_extent_cached(tree, cur, cur + iosize - 1,
2723 pg_offset += iosize;
2726 /* the get_extent function already copied into the page */
2727 if (test_range_bit(tree, cur, cur_end,
2728 EXTENT_UPTODATE, 1, NULL)) {
2729 check_page_uptodate(tree, page);
2730 unlock_extent(tree, cur, cur + iosize - 1);
2732 pg_offset += iosize;
2735 /* we have an inline extent but it didn't get marked up
2736 * to date. Error out
2738 if (block_start == EXTENT_MAP_INLINE) {
2740 unlock_extent(tree, cur, cur + iosize - 1);
2742 pg_offset += iosize;
2747 if (tree->ops && tree->ops->readpage_io_hook) {
2748 ret = tree->ops->readpage_io_hook(page, cur,
2752 unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
2754 ret = submit_extent_page(READ, tree, page,
2755 sector, disk_io_size, pg_offset,
2757 end_bio_extent_readpage, mirror_num,
2762 *bio_flags = this_bio_flag;
2767 unlock_extent(tree, cur, cur + iosize - 1);
2770 pg_offset += iosize;
2774 if (!PageError(page))
2775 SetPageUptodate(page);
2781 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
2782 get_extent_t *get_extent, int mirror_num)
2784 struct bio *bio = NULL;
2785 unsigned long bio_flags = 0;
2788 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
2791 ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
2795 static noinline void update_nr_written(struct page *page,
2796 struct writeback_control *wbc,
2797 unsigned long nr_written)
2799 wbc->nr_to_write -= nr_written;
2800 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
2801 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
2802 page->mapping->writeback_index = page->index + nr_written;
2806 * the writepage semantics are similar to regular writepage. extent
2807 * records are inserted to lock ranges in the tree, and as dirty areas
2808 * are found, they are marked writeback. Then the lock bits are removed
2809 * and the end_io handler clears the writeback ranges
2811 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
2814 struct inode *inode = page->mapping->host;
2815 struct extent_page_data *epd = data;
2816 struct extent_io_tree *tree = epd->tree;
2817 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2819 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2823 u64 last_byte = i_size_read(inode);
2827 struct extent_state *cached_state = NULL;
2828 struct extent_map *em;
2829 struct block_device *bdev;
2832 size_t pg_offset = 0;
2834 loff_t i_size = i_size_read(inode);
2835 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
2841 unsigned long nr_written = 0;
2842 bool fill_delalloc = true;
2844 if (wbc->sync_mode == WB_SYNC_ALL)
2845 write_flags = WRITE_SYNC;
2847 write_flags = WRITE;
2849 trace___extent_writepage(page, inode, wbc);
2851 WARN_ON(!PageLocked(page));
2853 ClearPageError(page);
2855 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2856 if (page->index > end_index ||
2857 (page->index == end_index && !pg_offset)) {
2858 page->mapping->a_ops->invalidatepage(page, 0);
2863 if (page->index == end_index) {
2866 userpage = kmap_atomic(page);
2867 memset(userpage + pg_offset, 0,
2868 PAGE_CACHE_SIZE - pg_offset);
2869 kunmap_atomic(userpage);
2870 flush_dcache_page(page);
2874 set_page_extent_mapped(page);
2876 if (!tree->ops || !tree->ops->fill_delalloc)
2877 fill_delalloc = false;
2879 delalloc_start = start;
2882 if (!epd->extent_locked && fill_delalloc) {
2883 u64 delalloc_to_write = 0;
2885 * make sure the wbc mapping index is at least updated
2888 update_nr_written(page, wbc, 0);
2890 while (delalloc_end < page_end) {
2891 nr_delalloc = find_lock_delalloc_range(inode, tree,
2896 if (nr_delalloc == 0) {
2897 delalloc_start = delalloc_end + 1;
2900 ret = tree->ops->fill_delalloc(inode, page,
2905 /* File system has been set read-only */
2911 * delalloc_end is already one less than the total
2912 * length, so we don't subtract one from
2915 delalloc_to_write += (delalloc_end - delalloc_start +
2918 delalloc_start = delalloc_end + 1;
2920 if (wbc->nr_to_write < delalloc_to_write) {
2923 if (delalloc_to_write < thresh * 2)
2924 thresh = delalloc_to_write;
2925 wbc->nr_to_write = min_t(u64, delalloc_to_write,
2929 /* did the fill delalloc function already unlock and start
2935 * we've unlocked the page, so we can't update
2936 * the mapping's writeback index, just update
2939 wbc->nr_to_write -= nr_written;
2943 if (tree->ops && tree->ops->writepage_start_hook) {
2944 ret = tree->ops->writepage_start_hook(page, start,
2947 /* Fixup worker will requeue */
2949 wbc->pages_skipped++;
2951 redirty_page_for_writepage(wbc, page);
2952 update_nr_written(page, wbc, nr_written);
2960 * we don't want to touch the inode after unlocking the page,
2961 * so we update the mapping writeback index now
2963 update_nr_written(page, wbc, nr_written + 1);
2966 if (last_byte <= start) {
2967 if (tree->ops && tree->ops->writepage_end_io_hook)
2968 tree->ops->writepage_end_io_hook(page, start,
2973 blocksize = inode->i_sb->s_blocksize;
2975 while (cur <= end) {
2976 if (cur >= last_byte) {
2977 if (tree->ops && tree->ops->writepage_end_io_hook)
2978 tree->ops->writepage_end_io_hook(page, cur,
2982 em = epd->get_extent(inode, page, pg_offset, cur,
2984 if (IS_ERR_OR_NULL(em)) {
2989 extent_offset = cur - em->start;
2990 BUG_ON(extent_map_end(em) <= cur);
2992 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2993 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2994 sector = (em->block_start + extent_offset) >> 9;
2996 block_start = em->block_start;
2997 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
2998 free_extent_map(em);
3002 * compressed and inline extents are written through other
3005 if (compressed || block_start == EXTENT_MAP_HOLE ||
3006 block_start == EXTENT_MAP_INLINE) {
3008 * end_io notification does not happen here for
3009 * compressed extents
3011 if (!compressed && tree->ops &&
3012 tree->ops->writepage_end_io_hook)
3013 tree->ops->writepage_end_io_hook(page, cur,
3016 else if (compressed) {
3017 /* we don't want to end_page_writeback on
3018 * a compressed extent. this happens
3025 pg_offset += iosize;
3028 /* leave this out until we have a page_mkwrite call */
3029 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
3030 EXTENT_DIRTY, 0, NULL)) {
3032 pg_offset += iosize;
3036 if (tree->ops && tree->ops->writepage_io_hook) {
3037 ret = tree->ops->writepage_io_hook(page, cur,
3045 unsigned long max_nr = end_index + 1;
3047 set_range_writeback(tree, cur, cur + iosize - 1);
3048 if (!PageWriteback(page)) {
3049 printk(KERN_ERR "btrfs warning page %lu not "
3050 "writeback, cur %llu end %llu\n",
3051 page->index, (unsigned long long)cur,
3052 (unsigned long long)end);
3055 ret = submit_extent_page(write_flags, tree, page,
3056 sector, iosize, pg_offset,
3057 bdev, &epd->bio, max_nr,
3058 end_bio_extent_writepage,
3064 pg_offset += iosize;
3069 /* make sure the mapping tag for page dirty gets cleared */
3070 set_page_writeback(page);
3071 end_page_writeback(page);
3077 /* drop our reference on any cached states */
3078 free_extent_state(cached_state);
3082 static int eb_wait(void *word)
3088 static void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3090 wait_on_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK, eb_wait,
3091 TASK_UNINTERRUPTIBLE);
3094 static int lock_extent_buffer_for_io(struct extent_buffer *eb,
3095 struct btrfs_fs_info *fs_info,
3096 struct extent_page_data *epd)
3098 unsigned long i, num_pages;
3102 if (!btrfs_try_tree_write_lock(eb)) {
3104 flush_write_bio(epd);
3105 btrfs_tree_lock(eb);
3108 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3109 btrfs_tree_unlock(eb);
3113 flush_write_bio(epd);
3117 wait_on_extent_buffer_writeback(eb);
3118 btrfs_tree_lock(eb);
3119 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3121 btrfs_tree_unlock(eb);
3126 * We need to do this to prevent races in people who check if the eb is
3127 * under IO since we can end up having no IO bits set for a short period
3130 spin_lock(&eb->refs_lock);
3131 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3132 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3133 spin_unlock(&eb->refs_lock);
3134 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3135 spin_lock(&fs_info->delalloc_lock);
3136 if (fs_info->dirty_metadata_bytes >= eb->len)
3137 fs_info->dirty_metadata_bytes -= eb->len;
3140 spin_unlock(&fs_info->delalloc_lock);
3143 spin_unlock(&eb->refs_lock);
3146 btrfs_tree_unlock(eb);
3151 num_pages = num_extent_pages(eb->start, eb->len);
3152 for (i = 0; i < num_pages; i++) {
3153 struct page *p = extent_buffer_page(eb, i);
3155 if (!trylock_page(p)) {
3157 flush_write_bio(epd);
3167 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3169 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3170 smp_mb__after_clear_bit();
3171 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3174 static void end_bio_extent_buffer_writepage(struct bio *bio, int err)
3176 int uptodate = err == 0;
3177 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
3178 struct extent_buffer *eb;
3182 struct page *page = bvec->bv_page;
3185 eb = (struct extent_buffer *)page->private;
3187 done = atomic_dec_and_test(&eb->io_pages);
3189 if (!uptodate || test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) {
3190 set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3191 ClearPageUptodate(page);
3195 end_page_writeback(page);
3200 end_extent_buffer_writeback(eb);
3201 } while (bvec >= bio->bi_io_vec);
3207 static int write_one_eb(struct extent_buffer *eb,
3208 struct btrfs_fs_info *fs_info,
3209 struct writeback_control *wbc,
3210 struct extent_page_data *epd)
3212 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3213 u64 offset = eb->start;
3214 unsigned long i, num_pages;
3215 unsigned long bio_flags = 0;
3216 int rw = (epd->sync_io ? WRITE_SYNC : WRITE);
3219 clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3220 num_pages = num_extent_pages(eb->start, eb->len);
3221 atomic_set(&eb->io_pages, num_pages);
3222 if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
3223 bio_flags = EXTENT_BIO_TREE_LOG;
3225 for (i = 0; i < num_pages; i++) {
3226 struct page *p = extent_buffer_page(eb, i);
3228 clear_page_dirty_for_io(p);
3229 set_page_writeback(p);
3230 ret = submit_extent_page(rw, eb->tree, p, offset >> 9,
3231 PAGE_CACHE_SIZE, 0, bdev, &epd->bio,
3232 -1, end_bio_extent_buffer_writepage,
3233 0, epd->bio_flags, bio_flags);
3234 epd->bio_flags = bio_flags;
3236 set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3238 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3239 end_extent_buffer_writeback(eb);
3243 offset += PAGE_CACHE_SIZE;
3244 update_nr_written(p, wbc, 1);
3248 if (unlikely(ret)) {
3249 for (; i < num_pages; i++) {
3250 struct page *p = extent_buffer_page(eb, i);
3258 int btree_write_cache_pages(struct address_space *mapping,
3259 struct writeback_control *wbc)
3261 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3262 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3263 struct extent_buffer *eb, *prev_eb = NULL;
3264 struct extent_page_data epd = {
3268 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3273 int nr_to_write_done = 0;
3274 struct pagevec pvec;
3277 pgoff_t end; /* Inclusive */
3281 pagevec_init(&pvec, 0);
3282 if (wbc->range_cyclic) {
3283 index = mapping->writeback_index; /* Start from prev offset */
3286 index = wbc->range_start >> PAGE_CACHE_SHIFT;
3287 end = wbc->range_end >> PAGE_CACHE_SHIFT;
3290 if (wbc->sync_mode == WB_SYNC_ALL)
3291 tag = PAGECACHE_TAG_TOWRITE;
3293 tag = PAGECACHE_TAG_DIRTY;
3295 if (wbc->sync_mode == WB_SYNC_ALL)
3296 tag_pages_for_writeback(mapping, index, end);
3297 while (!done && !nr_to_write_done && (index <= end) &&
3298 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3299 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3303 for (i = 0; i < nr_pages; i++) {
3304 struct page *page = pvec.pages[i];
3306 if (!PagePrivate(page))
3309 if (!wbc->range_cyclic && page->index > end) {
3314 spin_lock(&mapping->private_lock);
3315 if (!PagePrivate(page)) {
3316 spin_unlock(&mapping->private_lock);
3320 eb = (struct extent_buffer *)page->private;
3323 * Shouldn't happen and normally this would be a BUG_ON
3324 * but no sense in crashing the users box for something
3325 * we can survive anyway.
3328 spin_unlock(&mapping->private_lock);
3333 if (eb == prev_eb) {
3334 spin_unlock(&mapping->private_lock);
3338 ret = atomic_inc_not_zero(&eb->refs);
3339 spin_unlock(&mapping->private_lock);
3344 ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
3346 free_extent_buffer(eb);
3350 ret = write_one_eb(eb, fs_info, wbc, &epd);
3353 free_extent_buffer(eb);
3356 free_extent_buffer(eb);
3359 * the filesystem may choose to bump up nr_to_write.
3360 * We have to make sure to honor the new nr_to_write
3363 nr_to_write_done = wbc->nr_to_write <= 0;
3365 pagevec_release(&pvec);
3368 if (!scanned && !done) {
3370 * We hit the last page and there is more work to be done: wrap
3371 * back to the start of the file
3377 flush_write_bio(&epd);
3382 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3383 * @mapping: address space structure to write
3384 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3385 * @writepage: function called for each page
3386 * @data: data passed to writepage function
3388 * If a page is already under I/O, write_cache_pages() skips it, even
3389 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3390 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3391 * and msync() need to guarantee that all the data which was dirty at the time
3392 * the call was made get new I/O started against them. If wbc->sync_mode is
3393 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3394 * existing IO to complete.
3396 static int extent_write_cache_pages(struct extent_io_tree *tree,
3397 struct address_space *mapping,
3398 struct writeback_control *wbc,
3399 writepage_t writepage, void *data,
3400 void (*flush_fn)(void *))
3402 struct inode *inode = mapping->host;
3405 int nr_to_write_done = 0;
3406 struct pagevec pvec;
3409 pgoff_t end; /* Inclusive */
3414 * We have to hold onto the inode so that ordered extents can do their
3415 * work when the IO finishes. The alternative to this is failing to add
3416 * an ordered extent if the igrab() fails there and that is a huge pain
3417 * to deal with, so instead just hold onto the inode throughout the
3418 * writepages operation. If it fails here we are freeing up the inode
3419 * anyway and we'd rather not waste our time writing out stuff that is
3420 * going to be truncated anyway.
3425 pagevec_init(&pvec, 0);
3426 if (wbc->range_cyclic) {
3427 index = mapping->writeback_index; /* Start from prev offset */
3430 index = wbc->range_start >> PAGE_CACHE_SHIFT;
3431 end = wbc->range_end >> PAGE_CACHE_SHIFT;
3434 if (wbc->sync_mode == WB_SYNC_ALL)
3435 tag = PAGECACHE_TAG_TOWRITE;
3437 tag = PAGECACHE_TAG_DIRTY;
3439 if (wbc->sync_mode == WB_SYNC_ALL)
3440 tag_pages_for_writeback(mapping, index, end);
3441 while (!done && !nr_to_write_done && (index <= end) &&
3442 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3443 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3447 for (i = 0; i < nr_pages; i++) {
3448 struct page *page = pvec.pages[i];
3451 * At this point we hold neither mapping->tree_lock nor
3452 * lock on the page itself: the page may be truncated or
3453 * invalidated (changing page->mapping to NULL), or even
3454 * swizzled back from swapper_space to tmpfs file
3458 tree->ops->write_cache_pages_lock_hook) {
3459 tree->ops->write_cache_pages_lock_hook(page,
3462 if (!trylock_page(page)) {
3468 if (unlikely(page->mapping != mapping)) {
3473 if (!wbc->range_cyclic && page->index > end) {
3479 if (wbc->sync_mode != WB_SYNC_NONE) {
3480 if (PageWriteback(page))
3482 wait_on_page_writeback(page);
3485 if (PageWriteback(page) ||
3486 !clear_page_dirty_for_io(page)) {
3491 ret = (*writepage)(page, wbc, data);
3493 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
3501 * the filesystem may choose to bump up nr_to_write.
3502 * We have to make sure to honor the new nr_to_write
3505 nr_to_write_done = wbc->nr_to_write <= 0;
3507 pagevec_release(&pvec);
3510 if (!scanned && !done) {
3512 * We hit the last page and there is more work to be done: wrap
3513 * back to the start of the file
3519 btrfs_add_delayed_iput(inode);
3523 static void flush_epd_write_bio(struct extent_page_data *epd)
3532 ret = submit_one_bio(rw, epd->bio, 0, epd->bio_flags);
3533 BUG_ON(ret < 0); /* -ENOMEM */
3538 static noinline void flush_write_bio(void *data)
3540 struct extent_page_data *epd = data;
3541 flush_epd_write_bio(epd);
3544 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
3545 get_extent_t *get_extent,
3546 struct writeback_control *wbc)
3549 struct extent_page_data epd = {
3552 .get_extent = get_extent,
3554 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3558 ret = __extent_writepage(page, wbc, &epd);
3560 flush_epd_write_bio(&epd);
3564 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
3565 u64 start, u64 end, get_extent_t *get_extent,
3569 struct address_space *mapping = inode->i_mapping;
3571 unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
3574 struct extent_page_data epd = {
3577 .get_extent = get_extent,
3579 .sync_io = mode == WB_SYNC_ALL,
3582 struct writeback_control wbc_writepages = {
3584 .nr_to_write = nr_pages * 2,
3585 .range_start = start,
3586 .range_end = end + 1,
3589 while (start <= end) {
3590 page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
3591 if (clear_page_dirty_for_io(page))
3592 ret = __extent_writepage(page, &wbc_writepages, &epd);
3594 if (tree->ops && tree->ops->writepage_end_io_hook)
3595 tree->ops->writepage_end_io_hook(page, start,
3596 start + PAGE_CACHE_SIZE - 1,
3600 page_cache_release(page);
3601 start += PAGE_CACHE_SIZE;
3604 flush_epd_write_bio(&epd);
3608 int extent_writepages(struct extent_io_tree *tree,
3609 struct address_space *mapping,
3610 get_extent_t *get_extent,
3611 struct writeback_control *wbc)
3614 struct extent_page_data epd = {
3617 .get_extent = get_extent,
3619 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3623 ret = extent_write_cache_pages(tree, mapping, wbc,
3624 __extent_writepage, &epd,
3626 flush_epd_write_bio(&epd);
3630 int extent_readpages(struct extent_io_tree *tree,
3631 struct address_space *mapping,
3632 struct list_head *pages, unsigned nr_pages,
3633 get_extent_t get_extent)
3635 struct bio *bio = NULL;
3637 unsigned long bio_flags = 0;
3638 struct page *pagepool[16];
3643 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
3644 page = list_entry(pages->prev, struct page, lru);
3646 prefetchw(&page->flags);
3647 list_del(&page->lru);
3648 if (add_to_page_cache_lru(page, mapping,
3649 page->index, GFP_NOFS)) {
3650 page_cache_release(page);
3654 pagepool[nr++] = page;
3655 if (nr < ARRAY_SIZE(pagepool))
3657 for (i = 0; i < nr; i++) {
3658 __extent_read_full_page(tree, pagepool[i], get_extent,
3659 &bio, 0, &bio_flags);
3660 page_cache_release(pagepool[i]);
3664 for (i = 0; i < nr; i++) {
3665 __extent_read_full_page(tree, pagepool[i], get_extent,
3666 &bio, 0, &bio_flags);
3667 page_cache_release(pagepool[i]);
3670 BUG_ON(!list_empty(pages));
3672 return submit_one_bio(READ, bio, 0, bio_flags);
3677 * basic invalidatepage code, this waits on any locked or writeback
3678 * ranges corresponding to the page, and then deletes any extent state
3679 * records from the tree
3681 int extent_invalidatepage(struct extent_io_tree *tree,
3682 struct page *page, unsigned long offset)
3684 struct extent_state *cached_state = NULL;
3685 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
3686 u64 end = start + PAGE_CACHE_SIZE - 1;
3687 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
3689 start += (offset + blocksize - 1) & ~(blocksize - 1);
3693 lock_extent_bits(tree, start, end, 0, &cached_state);
3694 wait_on_page_writeback(page);
3695 clear_extent_bit(tree, start, end,
3696 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
3697 EXTENT_DO_ACCOUNTING,
3698 1, 1, &cached_state, GFP_NOFS);
3703 * a helper for releasepage, this tests for areas of the page that
3704 * are locked or under IO and drops the related state bits if it is safe
3707 int try_release_extent_state(struct extent_map_tree *map,
3708 struct extent_io_tree *tree, struct page *page,
3711 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
3712 u64 end = start + PAGE_CACHE_SIZE - 1;
3715 if (test_range_bit(tree, start, end,
3716 EXTENT_IOBITS, 0, NULL))
3719 if ((mask & GFP_NOFS) == GFP_NOFS)
3722 * at this point we can safely clear everything except the
3723 * locked bit and the nodatasum bit
3725 ret = clear_extent_bit(tree, start, end,
3726 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
3729 /* if clear_extent_bit failed for enomem reasons,
3730 * we can't allow the release to continue.
3741 * a helper for releasepage. As long as there are no locked extents
3742 * in the range corresponding to the page, both state records and extent
3743 * map records are removed
3745 int try_release_extent_mapping(struct extent_map_tree *map,
3746 struct extent_io_tree *tree, struct page *page,
3749 struct extent_map *em;
3750 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
3751 u64 end = start + PAGE_CACHE_SIZE - 1;
3753 if ((mask & __GFP_WAIT) &&
3754 page->mapping->host->i_size > 16 * 1024 * 1024) {
3756 while (start <= end) {
3757 len = end - start + 1;
3758 write_lock(&map->lock);
3759 em = lookup_extent_mapping(map, start, len);
3761 write_unlock(&map->lock);
3764 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
3765 em->start != start) {
3766 write_unlock(&map->lock);
3767 free_extent_map(em);
3770 if (!test_range_bit(tree, em->start,
3771 extent_map_end(em) - 1,
3772 EXTENT_LOCKED | EXTENT_WRITEBACK,
3774 remove_extent_mapping(map, em);
3775 /* once for the rb tree */
3776 free_extent_map(em);
3778 start = extent_map_end(em);
3779 write_unlock(&map->lock);
3782 free_extent_map(em);
3785 return try_release_extent_state(map, tree, page, mask);
3789 * helper function for fiemap, which doesn't want to see any holes.
3790 * This maps until we find something past 'last'
3792 static struct extent_map *get_extent_skip_holes(struct inode *inode,
3795 get_extent_t *get_extent)
3797 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
3798 struct extent_map *em;
3805 len = last - offset;
3808 len = (len + sectorsize - 1) & ~(sectorsize - 1);
3809 em = get_extent(inode, NULL, 0, offset, len, 0);
3810 if (IS_ERR_OR_NULL(em))
3813 /* if this isn't a hole return it */
3814 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
3815 em->block_start != EXTENT_MAP_HOLE) {
3819 /* this is a hole, advance to the next extent */
3820 offset = extent_map_end(em);
3821 free_extent_map(em);
3828 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3829 __u64 start, __u64 len, get_extent_t *get_extent)
3833 u64 max = start + len;
3837 u64 last_for_get_extent = 0;
3839 u64 isize = i_size_read(inode);
3840 struct btrfs_key found_key;
3841 struct extent_map *em = NULL;
3842 struct extent_state *cached_state = NULL;
3843 struct btrfs_path *path;
3844 struct btrfs_file_extent_item *item;
3849 unsigned long emflags;
3854 path = btrfs_alloc_path();
3857 path->leave_spinning = 1;
3859 start = ALIGN(start, BTRFS_I(inode)->root->sectorsize);
3860 len = ALIGN(len, BTRFS_I(inode)->root->sectorsize);
3863 * lookup the last file extent. We're not using i_size here
3864 * because there might be preallocation past i_size
3866 ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
3867 path, btrfs_ino(inode), -1, 0);
3869 btrfs_free_path(path);
3874 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3875 struct btrfs_file_extent_item);
3876 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
3877 found_type = btrfs_key_type(&found_key);
3879 /* No extents, but there might be delalloc bits */
3880 if (found_key.objectid != btrfs_ino(inode) ||
3881 found_type != BTRFS_EXTENT_DATA_KEY) {
3882 /* have to trust i_size as the end */
3884 last_for_get_extent = isize;
3887 * remember the start of the last extent. There are a
3888 * bunch of different factors that go into the length of the
3889 * extent, so its much less complex to remember where it started
3891 last = found_key.offset;
3892 last_for_get_extent = last + 1;
3894 btrfs_free_path(path);
3897 * we might have some extents allocated but more delalloc past those
3898 * extents. so, we trust isize unless the start of the last extent is
3903 last_for_get_extent = isize;
3906 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
3909 em = get_extent_skip_holes(inode, start, last_for_get_extent,
3919 u64 offset_in_extent;
3921 /* break if the extent we found is outside the range */
3922 if (em->start >= max || extent_map_end(em) < off)
3926 * get_extent may return an extent that starts before our
3927 * requested range. We have to make sure the ranges
3928 * we return to fiemap always move forward and don't
3929 * overlap, so adjust the offsets here
3931 em_start = max(em->start, off);
3934 * record the offset from the start of the extent
3935 * for adjusting the disk offset below
3937 offset_in_extent = em_start - em->start;
3938 em_end = extent_map_end(em);
3939 em_len = em_end - em_start;
3940 emflags = em->flags;
3945 * bump off for our next call to get_extent
3947 off = extent_map_end(em);
3951 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
3953 flags |= FIEMAP_EXTENT_LAST;
3954 } else if (em->block_start == EXTENT_MAP_INLINE) {
3955 flags |= (FIEMAP_EXTENT_DATA_INLINE |
3956 FIEMAP_EXTENT_NOT_ALIGNED);
3957 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
3958 flags |= (FIEMAP_EXTENT_DELALLOC |
3959 FIEMAP_EXTENT_UNKNOWN);
3961 disko = em->block_start + offset_in_extent;
3963 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
3964 flags |= FIEMAP_EXTENT_ENCODED;
3966 free_extent_map(em);
3968 if ((em_start >= last) || em_len == (u64)-1 ||
3969 (last == (u64)-1 && isize <= em_end)) {
3970 flags |= FIEMAP_EXTENT_LAST;
3974 /* now scan forward to see if this is really the last extent. */
3975 em = get_extent_skip_holes(inode, off, last_for_get_extent,
3982 flags |= FIEMAP_EXTENT_LAST;
3985 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
3991 free_extent_map(em);
3993 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len,
3994 &cached_state, GFP_NOFS);
3998 static void __free_extent_buffer(struct extent_buffer *eb)
4001 unsigned long flags;
4002 spin_lock_irqsave(&leak_lock, flags);
4003 list_del(&eb->leak_list);
4004 spin_unlock_irqrestore(&leak_lock, flags);
4006 if (eb->pages && eb->pages != eb->inline_pages)
4008 kmem_cache_free(extent_buffer_cache, eb);
4011 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
4016 struct extent_buffer *eb = NULL;
4018 unsigned long flags;
4021 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
4028 rwlock_init(&eb->lock);
4029 atomic_set(&eb->write_locks, 0);
4030 atomic_set(&eb->read_locks, 0);
4031 atomic_set(&eb->blocking_readers, 0);
4032 atomic_set(&eb->blocking_writers, 0);
4033 atomic_set(&eb->spinning_readers, 0);
4034 atomic_set(&eb->spinning_writers, 0);
4035 eb->lock_nested = 0;
4036 init_waitqueue_head(&eb->write_lock_wq);
4037 init_waitqueue_head(&eb->read_lock_wq);
4040 spin_lock_irqsave(&leak_lock, flags);
4041 list_add(&eb->leak_list, &buffers);
4042 spin_unlock_irqrestore(&leak_lock, flags);
4044 spin_lock_init(&eb->refs_lock);
4045 atomic_set(&eb->refs, 1);
4046 atomic_set(&eb->io_pages, 0);
4048 if (len > MAX_INLINE_EXTENT_BUFFER_SIZE) {
4049 struct page **pages;
4050 int num_pages = (len + PAGE_CACHE_SIZE - 1) >>
4052 pages = kzalloc(num_pages, mask);
4054 __free_extent_buffer(eb);
4059 eb->pages = eb->inline_pages;
4065 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4069 struct extent_buffer *new;
4070 unsigned long num_pages = num_extent_pages(src->start, src->len);
4072 new = __alloc_extent_buffer(NULL, src->start, src->len, GFP_ATOMIC);
4076 for (i = 0; i < num_pages; i++) {
4077 p = alloc_page(GFP_ATOMIC);
4079 attach_extent_buffer_page(new, p);
4080 WARN_ON(PageDirty(p));
4085 copy_extent_buffer(new, src, 0, 0, src->len);
4086 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4087 set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
4092 struct extent_buffer *alloc_dummy_extent_buffer(u64 start, unsigned long len)
4094 struct extent_buffer *eb;
4095 unsigned long num_pages = num_extent_pages(0, len);
4098 eb = __alloc_extent_buffer(NULL, start, len, GFP_ATOMIC);
4102 for (i = 0; i < num_pages; i++) {
4103 eb->pages[i] = alloc_page(GFP_ATOMIC);
4107 set_extent_buffer_uptodate(eb);
4108 btrfs_set_header_nritems(eb, 0);
4109 set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4113 for (i--; i >= 0; i--)
4114 __free_page(eb->pages[i]);
4115 __free_extent_buffer(eb);
4119 static int extent_buffer_under_io(struct extent_buffer *eb)
4121 return (atomic_read(&eb->io_pages) ||
4122 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4123 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4127 * Helper for releasing extent buffer page.
4129 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
4130 unsigned long start_idx)
4132 unsigned long index;
4133 unsigned long num_pages;
4135 int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4137 BUG_ON(extent_buffer_under_io(eb));
4139 num_pages = num_extent_pages(eb->start, eb->len);
4140 index = start_idx + num_pages;
4141 if (start_idx >= index)
4146 page = extent_buffer_page(eb, index);
4147 if (page && mapped) {
4148 spin_lock(&page->mapping->private_lock);
4150 * We do this since we'll remove the pages after we've
4151 * removed the eb from the radix tree, so we could race
4152 * and have this page now attached to the new eb. So
4153 * only clear page_private if it's still connected to
4156 if (PagePrivate(page) &&
4157 page->private == (unsigned long)eb) {
4158 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4159 BUG_ON(PageDirty(page));
4160 BUG_ON(PageWriteback(page));
4162 * We need to make sure we haven't be attached
4165 ClearPagePrivate(page);
4166 set_page_private(page, 0);
4167 /* One for the page private */
4168 page_cache_release(page);
4170 spin_unlock(&page->mapping->private_lock);
4174 /* One for when we alloced the page */
4175 page_cache_release(page);
4177 } while (index != start_idx);
4181 * Helper for releasing the extent buffer.
4183 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4185 btrfs_release_extent_buffer_page(eb, 0);
4186 __free_extent_buffer(eb);
4189 static void check_buffer_tree_ref(struct extent_buffer *eb)
4191 /* the ref bit is tricky. We have to make sure it is set
4192 * if we have the buffer dirty. Otherwise the
4193 * code to free a buffer can end up dropping a dirty
4196 * Once the ref bit is set, it won't go away while the
4197 * buffer is dirty or in writeback, and it also won't
4198 * go away while we have the reference count on the
4201 * We can't just set the ref bit without bumping the
4202 * ref on the eb because free_extent_buffer might
4203 * see the ref bit and try to clear it. If this happens
4204 * free_extent_buffer might end up dropping our original
4205 * ref by mistake and freeing the page before we are able
4206 * to add one more ref.
4208 * So bump the ref count first, then set the bit. If someone
4209 * beat us to it, drop the ref we added.
4211 spin_lock(&eb->refs_lock);
4212 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4213 atomic_inc(&eb->refs);
4214 spin_unlock(&eb->refs_lock);
4217 static void mark_extent_buffer_accessed(struct extent_buffer *eb)
4219 unsigned long num_pages, i;
4221 check_buffer_tree_ref(eb);
4223 num_pages = num_extent_pages(eb->start, eb->len);
4224 for (i = 0; i < num_pages; i++) {
4225 struct page *p = extent_buffer_page(eb, i);
4226 mark_page_accessed(p);
4230 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
4231 u64 start, unsigned long len)
4233 unsigned long num_pages = num_extent_pages(start, len);
4235 unsigned long index = start >> PAGE_CACHE_SHIFT;
4236 struct extent_buffer *eb;
4237 struct extent_buffer *exists = NULL;
4239 struct address_space *mapping = tree->mapping;
4244 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4245 if (eb && atomic_inc_not_zero(&eb->refs)) {
4247 mark_extent_buffer_accessed(eb);
4252 eb = __alloc_extent_buffer(tree, start, len, GFP_NOFS);
4256 for (i = 0; i < num_pages; i++, index++) {
4257 p = find_or_create_page(mapping, index, GFP_NOFS);
4261 spin_lock(&mapping->private_lock);
4262 if (PagePrivate(p)) {
4264 * We could have already allocated an eb for this page
4265 * and attached one so lets see if we can get a ref on
4266 * the existing eb, and if we can we know it's good and
4267 * we can just return that one, else we know we can just
4268 * overwrite page->private.
4270 exists = (struct extent_buffer *)p->private;
4271 if (atomic_inc_not_zero(&exists->refs)) {
4272 spin_unlock(&mapping->private_lock);
4274 page_cache_release(p);
4275 mark_extent_buffer_accessed(exists);
4280 * Do this so attach doesn't complain and we need to
4281 * drop the ref the old guy had.
4283 ClearPagePrivate(p);
4284 WARN_ON(PageDirty(p));
4285 page_cache_release(p);
4287 attach_extent_buffer_page(eb, p);
4288 spin_unlock(&mapping->private_lock);
4289 WARN_ON(PageDirty(p));
4290 mark_page_accessed(p);
4292 if (!PageUptodate(p))
4296 * see below about how we avoid a nasty race with release page
4297 * and why we unlock later
4301 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4303 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
4307 spin_lock(&tree->buffer_lock);
4308 ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
4309 if (ret == -EEXIST) {
4310 exists = radix_tree_lookup(&tree->buffer,
4311 start >> PAGE_CACHE_SHIFT);
4312 if (!atomic_inc_not_zero(&exists->refs)) {
4313 spin_unlock(&tree->buffer_lock);
4314 radix_tree_preload_end();
4318 spin_unlock(&tree->buffer_lock);
4319 radix_tree_preload_end();
4320 mark_extent_buffer_accessed(exists);
4323 /* add one reference for the tree */
4324 check_buffer_tree_ref(eb);
4325 spin_unlock(&tree->buffer_lock);
4326 radix_tree_preload_end();
4329 * there is a race where release page may have
4330 * tried to find this extent buffer in the radix
4331 * but failed. It will tell the VM it is safe to
4332 * reclaim the, and it will clear the page private bit.
4333 * We must make sure to set the page private bit properly
4334 * after the extent buffer is in the radix tree so
4335 * it doesn't get lost
4337 SetPageChecked(eb->pages[0]);
4338 for (i = 1; i < num_pages; i++) {
4339 p = extent_buffer_page(eb, i);
4340 ClearPageChecked(p);
4343 unlock_page(eb->pages[0]);
4347 for (i = 0; i < num_pages; i++) {
4349 unlock_page(eb->pages[i]);
4352 WARN_ON(!atomic_dec_and_test(&eb->refs));
4353 btrfs_release_extent_buffer(eb);
4357 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
4358 u64 start, unsigned long len)
4360 struct extent_buffer *eb;
4363 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4364 if (eb && atomic_inc_not_zero(&eb->refs)) {
4366 mark_extent_buffer_accessed(eb);
4374 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
4376 struct extent_buffer *eb =
4377 container_of(head, struct extent_buffer, rcu_head);
4379 __free_extent_buffer(eb);
4382 /* Expects to have eb->eb_lock already held */
4383 static int release_extent_buffer(struct extent_buffer *eb, gfp_t mask)
4385 WARN_ON(atomic_read(&eb->refs) == 0);
4386 if (atomic_dec_and_test(&eb->refs)) {
4387 if (test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags)) {
4388 spin_unlock(&eb->refs_lock);
4390 struct extent_io_tree *tree = eb->tree;
4392 spin_unlock(&eb->refs_lock);
4394 spin_lock(&tree->buffer_lock);
4395 radix_tree_delete(&tree->buffer,
4396 eb->start >> PAGE_CACHE_SHIFT);
4397 spin_unlock(&tree->buffer_lock);
4400 /* Should be safe to release our pages at this point */
4401 btrfs_release_extent_buffer_page(eb, 0);
4402 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
4405 spin_unlock(&eb->refs_lock);
4410 void free_extent_buffer(struct extent_buffer *eb)
4415 spin_lock(&eb->refs_lock);
4416 if (atomic_read(&eb->refs) == 2 &&
4417 test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
4418 atomic_dec(&eb->refs);
4420 if (atomic_read(&eb->refs) == 2 &&
4421 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
4422 !extent_buffer_under_io(eb) &&
4423 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4424 atomic_dec(&eb->refs);
4427 * I know this is terrible, but it's temporary until we stop tracking
4428 * the uptodate bits and such for the extent buffers.
4430 release_extent_buffer(eb, GFP_ATOMIC);
4433 void free_extent_buffer_stale(struct extent_buffer *eb)
4438 spin_lock(&eb->refs_lock);
4439 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
4441 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
4442 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4443 atomic_dec(&eb->refs);
4444 release_extent_buffer(eb, GFP_NOFS);
4447 void clear_extent_buffer_dirty(struct extent_buffer *eb)
4450 unsigned long num_pages;
4453 num_pages = num_extent_pages(eb->start, eb->len);
4455 for (i = 0; i < num_pages; i++) {
4456 page = extent_buffer_page(eb, i);
4457 if (!PageDirty(page))
4461 WARN_ON(!PagePrivate(page));
4463 clear_page_dirty_for_io(page);
4464 spin_lock_irq(&page->mapping->tree_lock);
4465 if (!PageDirty(page)) {
4466 radix_tree_tag_clear(&page->mapping->page_tree,
4468 PAGECACHE_TAG_DIRTY);
4470 spin_unlock_irq(&page->mapping->tree_lock);
4471 ClearPageError(page);
4474 WARN_ON(atomic_read(&eb->refs) == 0);
4477 int set_extent_buffer_dirty(struct extent_buffer *eb)
4480 unsigned long num_pages;
4483 check_buffer_tree_ref(eb);
4485 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
4487 num_pages = num_extent_pages(eb->start, eb->len);
4488 WARN_ON(atomic_read(&eb->refs) == 0);
4489 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
4491 for (i = 0; i < num_pages; i++)
4492 set_page_dirty(extent_buffer_page(eb, i));
4496 static int range_straddles_pages(u64 start, u64 len)
4498 if (len < PAGE_CACHE_SIZE)
4500 if (start & (PAGE_CACHE_SIZE - 1))
4502 if ((start + len) & (PAGE_CACHE_SIZE - 1))
4507 int clear_extent_buffer_uptodate(struct extent_buffer *eb)
4511 unsigned long num_pages;
4513 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4514 num_pages = num_extent_pages(eb->start, eb->len);
4515 for (i = 0; i < num_pages; i++) {
4516 page = extent_buffer_page(eb, i);
4518 ClearPageUptodate(page);
4523 int set_extent_buffer_uptodate(struct extent_buffer *eb)
4527 unsigned long num_pages;
4529 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4530 num_pages = num_extent_pages(eb->start, eb->len);
4531 for (i = 0; i < num_pages; i++) {
4532 page = extent_buffer_page(eb, i);
4533 SetPageUptodate(page);
4538 int extent_range_uptodate(struct extent_io_tree *tree,
4543 int pg_uptodate = 1;
4545 unsigned long index;
4547 if (range_straddles_pages(start, end - start + 1)) {
4548 ret = test_range_bit(tree, start, end,
4549 EXTENT_UPTODATE, 1, NULL);
4553 while (start <= end) {
4554 index = start >> PAGE_CACHE_SHIFT;
4555 page = find_get_page(tree->mapping, index);
4558 uptodate = PageUptodate(page);
4559 page_cache_release(page);
4564 start += PAGE_CACHE_SIZE;
4569 int extent_buffer_uptodate(struct extent_buffer *eb)
4571 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4574 int read_extent_buffer_pages(struct extent_io_tree *tree,
4575 struct extent_buffer *eb, u64 start, int wait,
4576 get_extent_t *get_extent, int mirror_num)
4579 unsigned long start_i;
4583 int locked_pages = 0;
4584 int all_uptodate = 1;
4585 unsigned long num_pages;
4586 unsigned long num_reads = 0;
4587 struct bio *bio = NULL;
4588 unsigned long bio_flags = 0;
4590 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
4594 WARN_ON(start < eb->start);
4595 start_i = (start >> PAGE_CACHE_SHIFT) -
4596 (eb->start >> PAGE_CACHE_SHIFT);
4601 num_pages = num_extent_pages(eb->start, eb->len);
4602 for (i = start_i; i < num_pages; i++) {
4603 page = extent_buffer_page(eb, i);
4604 if (wait == WAIT_NONE) {
4605 if (!trylock_page(page))
4611 if (!PageUptodate(page)) {
4618 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4622 clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
4623 eb->read_mirror = 0;
4624 atomic_set(&eb->io_pages, num_reads);
4625 for (i = start_i; i < num_pages; i++) {
4626 page = extent_buffer_page(eb, i);
4627 if (!PageUptodate(page)) {
4628 ClearPageError(page);
4629 err = __extent_read_full_page(tree, page,
4631 mirror_num, &bio_flags);
4640 err = submit_one_bio(READ, bio, mirror_num, bio_flags);
4645 if (ret || wait != WAIT_COMPLETE)
4648 for (i = start_i; i < num_pages; i++) {
4649 page = extent_buffer_page(eb, i);
4650 wait_on_page_locked(page);
4651 if (!PageUptodate(page))
4659 while (locked_pages > 0) {
4660 page = extent_buffer_page(eb, i);
4668 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
4669 unsigned long start,
4676 char *dst = (char *)dstv;
4677 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4678 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4680 WARN_ON(start > eb->len);
4681 WARN_ON(start + len > eb->start + eb->len);
4683 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4686 page = extent_buffer_page(eb, i);
4688 cur = min(len, (PAGE_CACHE_SIZE - offset));
4689 kaddr = page_address(page);
4690 memcpy(dst, kaddr + offset, cur);
4699 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
4700 unsigned long min_len, char **map,
4701 unsigned long *map_start,
4702 unsigned long *map_len)
4704 size_t offset = start & (PAGE_CACHE_SIZE - 1);
4707 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4708 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4709 unsigned long end_i = (start_offset + start + min_len - 1) >>
4716 offset = start_offset;
4720 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
4723 if (start + min_len > eb->len) {
4724 printk(KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
4725 "wanted %lu %lu\n", (unsigned long long)eb->start,
4726 eb->len, start, min_len);
4731 p = extent_buffer_page(eb, i);
4732 kaddr = page_address(p);
4733 *map = kaddr + offset;
4734 *map_len = PAGE_CACHE_SIZE - offset;
4738 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
4739 unsigned long start,
4746 char *ptr = (char *)ptrv;
4747 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4748 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4751 WARN_ON(start > eb->len);
4752 WARN_ON(start + len > eb->start + eb->len);
4754 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4757 page = extent_buffer_page(eb, i);
4759 cur = min(len, (PAGE_CACHE_SIZE - offset));
4761 kaddr = page_address(page);
4762 ret = memcmp(ptr, kaddr + offset, cur);
4774 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
4775 unsigned long start, unsigned long len)
4781 char *src = (char *)srcv;
4782 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4783 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4785 WARN_ON(start > eb->len);
4786 WARN_ON(start + len > eb->start + eb->len);
4788 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4791 page = extent_buffer_page(eb, i);
4792 WARN_ON(!PageUptodate(page));
4794 cur = min(len, PAGE_CACHE_SIZE - offset);
4795 kaddr = page_address(page);
4796 memcpy(kaddr + offset, src, cur);
4805 void memset_extent_buffer(struct extent_buffer *eb, char c,
4806 unsigned long start, unsigned long len)
4812 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4813 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4815 WARN_ON(start > eb->len);
4816 WARN_ON(start + len > eb->start + eb->len);
4818 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4821 page = extent_buffer_page(eb, i);
4822 WARN_ON(!PageUptodate(page));
4824 cur = min(len, PAGE_CACHE_SIZE - offset);
4825 kaddr = page_address(page);
4826 memset(kaddr + offset, c, cur);
4834 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
4835 unsigned long dst_offset, unsigned long src_offset,
4838 u64 dst_len = dst->len;
4843 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4844 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4846 WARN_ON(src->len != dst_len);
4848 offset = (start_offset + dst_offset) &
4849 ((unsigned long)PAGE_CACHE_SIZE - 1);
4852 page = extent_buffer_page(dst, i);
4853 WARN_ON(!PageUptodate(page));
4855 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
4857 kaddr = page_address(page);
4858 read_extent_buffer(src, kaddr + offset, src_offset, cur);
4867 static void move_pages(struct page *dst_page, struct page *src_page,
4868 unsigned long dst_off, unsigned long src_off,
4871 char *dst_kaddr = page_address(dst_page);
4872 if (dst_page == src_page) {
4873 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
4875 char *src_kaddr = page_address(src_page);
4876 char *p = dst_kaddr + dst_off + len;
4877 char *s = src_kaddr + src_off + len;
4884 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
4886 unsigned long distance = (src > dst) ? src - dst : dst - src;
4887 return distance < len;
4890 static void copy_pages(struct page *dst_page, struct page *src_page,
4891 unsigned long dst_off, unsigned long src_off,
4894 char *dst_kaddr = page_address(dst_page);
4896 int must_memmove = 0;
4898 if (dst_page != src_page) {
4899 src_kaddr = page_address(src_page);
4901 src_kaddr = dst_kaddr;
4902 if (areas_overlap(src_off, dst_off, len))
4907 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
4909 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
4912 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
4913 unsigned long src_offset, unsigned long len)
4916 size_t dst_off_in_page;
4917 size_t src_off_in_page;
4918 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4919 unsigned long dst_i;
4920 unsigned long src_i;
4922 if (src_offset + len > dst->len) {
4923 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4924 "len %lu dst len %lu\n", src_offset, len, dst->len);
4927 if (dst_offset + len > dst->len) {
4928 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4929 "len %lu dst len %lu\n", dst_offset, len, dst->len);
4934 dst_off_in_page = (start_offset + dst_offset) &
4935 ((unsigned long)PAGE_CACHE_SIZE - 1);
4936 src_off_in_page = (start_offset + src_offset) &
4937 ((unsigned long)PAGE_CACHE_SIZE - 1);
4939 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4940 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
4942 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
4944 cur = min_t(unsigned long, cur,
4945 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
4947 copy_pages(extent_buffer_page(dst, dst_i),
4948 extent_buffer_page(dst, src_i),
4949 dst_off_in_page, src_off_in_page, cur);
4957 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
4958 unsigned long src_offset, unsigned long len)
4961 size_t dst_off_in_page;
4962 size_t src_off_in_page;
4963 unsigned long dst_end = dst_offset + len - 1;
4964 unsigned long src_end = src_offset + len - 1;
4965 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4966 unsigned long dst_i;
4967 unsigned long src_i;
4969 if (src_offset + len > dst->len) {
4970 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4971 "len %lu len %lu\n", src_offset, len, dst->len);
4974 if (dst_offset + len > dst->len) {
4975 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4976 "len %lu len %lu\n", dst_offset, len, dst->len);
4979 if (dst_offset < src_offset) {
4980 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
4984 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
4985 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
4987 dst_off_in_page = (start_offset + dst_end) &
4988 ((unsigned long)PAGE_CACHE_SIZE - 1);
4989 src_off_in_page = (start_offset + src_end) &
4990 ((unsigned long)PAGE_CACHE_SIZE - 1);
4992 cur = min_t(unsigned long, len, src_off_in_page + 1);
4993 cur = min(cur, dst_off_in_page + 1);
4994 move_pages(extent_buffer_page(dst, dst_i),
4995 extent_buffer_page(dst, src_i),
4996 dst_off_in_page - cur + 1,
4997 src_off_in_page - cur + 1, cur);
5005 int try_release_extent_buffer(struct page *page, gfp_t mask)
5007 struct extent_buffer *eb;
5010 * We need to make sure noboody is attaching this page to an eb right
5013 spin_lock(&page->mapping->private_lock);
5014 if (!PagePrivate(page)) {
5015 spin_unlock(&page->mapping->private_lock);
5019 eb = (struct extent_buffer *)page->private;
5023 * This is a little awful but should be ok, we need to make sure that
5024 * the eb doesn't disappear out from under us while we're looking at
5027 spin_lock(&eb->refs_lock);
5028 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5029 spin_unlock(&eb->refs_lock);
5030 spin_unlock(&page->mapping->private_lock);
5033 spin_unlock(&page->mapping->private_lock);
5035 if ((mask & GFP_NOFS) == GFP_NOFS)
5039 * If tree ref isn't set then we know the ref on this eb is a real ref,
5040 * so just return, this page will likely be freed soon anyway.
5042 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
5043 spin_unlock(&eb->refs_lock);
5047 return release_extent_buffer(eb, mask);