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 WARN(1, KERN_ERR "btrfs end < start %llu %llu\n",
346 (unsigned long long)end,
347 (unsigned long long)start);
348 state->start = start;
351 set_state_bits(tree, state, bits);
353 node = tree_insert(&tree->state, end, &state->rb_node);
355 struct extent_state *found;
356 found = rb_entry(node, struct extent_state, rb_node);
357 printk(KERN_ERR "btrfs found node %llu %llu on insert of "
358 "%llu %llu\n", (unsigned long long)found->start,
359 (unsigned long long)found->end,
360 (unsigned long long)start, (unsigned long long)end);
364 merge_state(tree, state);
368 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
371 if (tree->ops && tree->ops->split_extent_hook)
372 tree->ops->split_extent_hook(tree->mapping->host, orig, split);
376 * split a given extent state struct in two, inserting the preallocated
377 * struct 'prealloc' as the newly created second half. 'split' indicates an
378 * offset inside 'orig' where it should be split.
381 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
382 * are two extent state structs in the tree:
383 * prealloc: [orig->start, split - 1]
384 * orig: [ split, orig->end ]
386 * The tree locks are not taken by this function. They need to be held
389 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
390 struct extent_state *prealloc, u64 split)
392 struct rb_node *node;
394 split_cb(tree, orig, split);
396 prealloc->start = orig->start;
397 prealloc->end = split - 1;
398 prealloc->state = orig->state;
401 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
403 free_extent_state(prealloc);
406 prealloc->tree = tree;
410 static struct extent_state *next_state(struct extent_state *state)
412 struct rb_node *next = rb_next(&state->rb_node);
414 return rb_entry(next, struct extent_state, rb_node);
420 * utility function to clear some bits in an extent state struct.
421 * it will optionally wake up any one waiting on this state (wake == 1).
423 * If no bits are set on the state struct after clearing things, the
424 * struct is freed and removed from the tree
426 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
427 struct extent_state *state,
430 struct extent_state *next;
431 int bits_to_clear = *bits & ~EXTENT_CTLBITS;
433 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
434 u64 range = state->end - state->start + 1;
435 WARN_ON(range > tree->dirty_bytes);
436 tree->dirty_bytes -= range;
438 clear_state_cb(tree, state, bits);
439 state->state &= ~bits_to_clear;
442 if (state->state == 0) {
443 next = next_state(state);
445 rb_erase(&state->rb_node, &tree->state);
447 free_extent_state(state);
452 merge_state(tree, state);
453 next = next_state(state);
458 static struct extent_state *
459 alloc_extent_state_atomic(struct extent_state *prealloc)
462 prealloc = alloc_extent_state(GFP_ATOMIC);
467 void extent_io_tree_panic(struct extent_io_tree *tree, int err)
469 btrfs_panic(tree_fs_info(tree), err, "Locking error: "
470 "Extent tree was modified by another "
471 "thread while locked.");
475 * clear some bits on a range in the tree. This may require splitting
476 * or inserting elements in the tree, so the gfp mask is used to
477 * indicate which allocations or sleeping are allowed.
479 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
480 * the given range from the tree regardless of state (ie for truncate).
482 * the range [start, end] is inclusive.
484 * This takes the tree lock, and returns 0 on success and < 0 on error.
486 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
487 int bits, int wake, int delete,
488 struct extent_state **cached_state,
491 struct extent_state *state;
492 struct extent_state *cached;
493 struct extent_state *prealloc = NULL;
494 struct rb_node *node;
500 bits |= ~EXTENT_CTLBITS;
501 bits |= EXTENT_FIRST_DELALLOC;
503 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
506 if (!prealloc && (mask & __GFP_WAIT)) {
507 prealloc = alloc_extent_state(mask);
512 spin_lock(&tree->lock);
514 cached = *cached_state;
517 *cached_state = NULL;
521 if (cached && cached->tree && cached->start <= start &&
522 cached->end > start) {
524 atomic_dec(&cached->refs);
529 free_extent_state(cached);
532 * this search will find the extents that end after
535 node = tree_search(tree, start);
538 state = rb_entry(node, struct extent_state, rb_node);
540 if (state->start > end)
542 WARN_ON(state->end < start);
543 last_end = state->end;
545 /* the state doesn't have the wanted bits, go ahead */
546 if (!(state->state & bits)) {
547 state = next_state(state);
552 * | ---- desired range ---- |
554 * | ------------- state -------------- |
556 * We need to split the extent we found, and may flip
557 * bits on second half.
559 * If the extent we found extends past our range, we
560 * just split and search again. It'll get split again
561 * the next time though.
563 * If the extent we found is inside our range, we clear
564 * the desired bit on it.
567 if (state->start < start) {
568 prealloc = alloc_extent_state_atomic(prealloc);
570 err = split_state(tree, state, prealloc, start);
572 extent_io_tree_panic(tree, err);
577 if (state->end <= end) {
578 state = clear_state_bit(tree, state, &bits, wake);
584 * | ---- desired range ---- |
586 * We need to split the extent, and clear the bit
589 if (state->start <= end && state->end > end) {
590 prealloc = alloc_extent_state_atomic(prealloc);
592 err = split_state(tree, state, prealloc, end + 1);
594 extent_io_tree_panic(tree, err);
599 clear_state_bit(tree, prealloc, &bits, wake);
605 state = clear_state_bit(tree, state, &bits, wake);
607 if (last_end == (u64)-1)
609 start = last_end + 1;
610 if (start <= end && state && !need_resched())
615 spin_unlock(&tree->lock);
617 free_extent_state(prealloc);
624 spin_unlock(&tree->lock);
625 if (mask & __GFP_WAIT)
630 static void wait_on_state(struct extent_io_tree *tree,
631 struct extent_state *state)
632 __releases(tree->lock)
633 __acquires(tree->lock)
636 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
637 spin_unlock(&tree->lock);
639 spin_lock(&tree->lock);
640 finish_wait(&state->wq, &wait);
644 * waits for one or more bits to clear on a range in the state tree.
645 * The range [start, end] is inclusive.
646 * The tree lock is taken by this function
648 void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
650 struct extent_state *state;
651 struct rb_node *node;
653 spin_lock(&tree->lock);
657 * this search will find all the extents that end after
660 node = tree_search(tree, start);
664 state = rb_entry(node, struct extent_state, rb_node);
666 if (state->start > end)
669 if (state->state & bits) {
670 start = state->start;
671 atomic_inc(&state->refs);
672 wait_on_state(tree, state);
673 free_extent_state(state);
676 start = state->end + 1;
681 cond_resched_lock(&tree->lock);
684 spin_unlock(&tree->lock);
687 static void set_state_bits(struct extent_io_tree *tree,
688 struct extent_state *state,
691 int bits_to_set = *bits & ~EXTENT_CTLBITS;
693 set_state_cb(tree, state, bits);
694 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
695 u64 range = state->end - state->start + 1;
696 tree->dirty_bytes += range;
698 state->state |= bits_to_set;
701 static void cache_state(struct extent_state *state,
702 struct extent_state **cached_ptr)
704 if (cached_ptr && !(*cached_ptr)) {
705 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
707 atomic_inc(&state->refs);
712 static void uncache_state(struct extent_state **cached_ptr)
714 if (cached_ptr && (*cached_ptr)) {
715 struct extent_state *state = *cached_ptr;
717 free_extent_state(state);
722 * set some bits on a range in the tree. This may require allocations or
723 * sleeping, so the gfp mask is used to indicate what is allowed.
725 * If any of the exclusive bits are set, this will fail with -EEXIST if some
726 * part of the range already has the desired bits set. The start of the
727 * existing range is returned in failed_start in this case.
729 * [start, end] is inclusive This takes the tree lock.
732 static int __must_check
733 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
734 int bits, int exclusive_bits, u64 *failed_start,
735 struct extent_state **cached_state, gfp_t mask)
737 struct extent_state *state;
738 struct extent_state *prealloc = NULL;
739 struct rb_node *node;
744 bits |= EXTENT_FIRST_DELALLOC;
746 if (!prealloc && (mask & __GFP_WAIT)) {
747 prealloc = alloc_extent_state(mask);
751 spin_lock(&tree->lock);
752 if (cached_state && *cached_state) {
753 state = *cached_state;
754 if (state->start <= start && state->end > start &&
756 node = &state->rb_node;
761 * this search will find all the extents that end after
764 node = tree_search(tree, start);
766 prealloc = alloc_extent_state_atomic(prealloc);
768 err = insert_state(tree, prealloc, start, end, &bits);
770 extent_io_tree_panic(tree, err);
775 state = rb_entry(node, struct extent_state, rb_node);
777 last_start = state->start;
778 last_end = state->end;
781 * | ---- desired range ---- |
784 * Just lock what we found and keep going
786 if (state->start == start && state->end <= end) {
787 if (state->state & exclusive_bits) {
788 *failed_start = state->start;
793 set_state_bits(tree, state, &bits);
794 cache_state(state, cached_state);
795 merge_state(tree, state);
796 if (last_end == (u64)-1)
798 start = last_end + 1;
799 state = next_state(state);
800 if (start < end && state && state->start == start &&
807 * | ---- desired range ---- |
810 * | ------------- state -------------- |
812 * We need to split the extent we found, and may flip bits on
815 * If the extent we found extends past our
816 * range, we just split and search again. It'll get split
817 * again the next time though.
819 * If the extent we found is inside our range, we set the
822 if (state->start < start) {
823 if (state->state & exclusive_bits) {
824 *failed_start = start;
829 prealloc = alloc_extent_state_atomic(prealloc);
831 err = split_state(tree, state, prealloc, start);
833 extent_io_tree_panic(tree, err);
838 if (state->end <= end) {
839 set_state_bits(tree, state, &bits);
840 cache_state(state, cached_state);
841 merge_state(tree, state);
842 if (last_end == (u64)-1)
844 start = last_end + 1;
845 state = next_state(state);
846 if (start < end && state && state->start == start &&
853 * | ---- desired range ---- |
854 * | state | or | state |
856 * There's a hole, we need to insert something in it and
857 * ignore the extent we found.
859 if (state->start > start) {
861 if (end < last_start)
864 this_end = last_start - 1;
866 prealloc = alloc_extent_state_atomic(prealloc);
870 * Avoid to free 'prealloc' if it can be merged with
873 err = insert_state(tree, prealloc, start, this_end,
876 extent_io_tree_panic(tree, err);
878 cache_state(prealloc, cached_state);
880 start = this_end + 1;
884 * | ---- desired range ---- |
886 * We need to split the extent, and set the bit
889 if (state->start <= end && state->end > end) {
890 if (state->state & exclusive_bits) {
891 *failed_start = start;
896 prealloc = alloc_extent_state_atomic(prealloc);
898 err = split_state(tree, state, prealloc, end + 1);
900 extent_io_tree_panic(tree, err);
902 set_state_bits(tree, prealloc, &bits);
903 cache_state(prealloc, cached_state);
904 merge_state(tree, prealloc);
912 spin_unlock(&tree->lock);
914 free_extent_state(prealloc);
921 spin_unlock(&tree->lock);
922 if (mask & __GFP_WAIT)
927 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits,
928 u64 *failed_start, struct extent_state **cached_state,
931 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
937 * convert_extent_bit - convert all bits in a given range from one bit to
939 * @tree: the io tree to search
940 * @start: the start offset in bytes
941 * @end: the end offset in bytes (inclusive)
942 * @bits: the bits to set in this range
943 * @clear_bits: the bits to clear in this range
944 * @cached_state: state that we're going to cache
945 * @mask: the allocation mask
947 * This will go through and set bits for the given range. If any states exist
948 * already in this range they are set with the given bit and cleared of the
949 * clear_bits. This is only meant to be used by things that are mergeable, ie
950 * converting from say DELALLOC to DIRTY. This is not meant to be used with
951 * boundary bits like LOCK.
953 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
954 int bits, int clear_bits,
955 struct extent_state **cached_state, gfp_t mask)
957 struct extent_state *state;
958 struct extent_state *prealloc = NULL;
959 struct rb_node *node;
965 if (!prealloc && (mask & __GFP_WAIT)) {
966 prealloc = alloc_extent_state(mask);
971 spin_lock(&tree->lock);
972 if (cached_state && *cached_state) {
973 state = *cached_state;
974 if (state->start <= start && state->end > start &&
976 node = &state->rb_node;
982 * this search will find all the extents that end after
985 node = tree_search(tree, start);
987 prealloc = alloc_extent_state_atomic(prealloc);
992 err = insert_state(tree, prealloc, start, end, &bits);
995 extent_io_tree_panic(tree, err);
998 state = rb_entry(node, struct extent_state, rb_node);
1000 last_start = state->start;
1001 last_end = state->end;
1004 * | ---- desired range ---- |
1007 * Just lock what we found and keep going
1009 if (state->start == start && state->end <= end) {
1010 set_state_bits(tree, state, &bits);
1011 cache_state(state, cached_state);
1012 state = clear_state_bit(tree, state, &clear_bits, 0);
1013 if (last_end == (u64)-1)
1015 start = last_end + 1;
1016 if (start < end && state && state->start == start &&
1023 * | ---- desired range ---- |
1026 * | ------------- state -------------- |
1028 * We need to split the extent we found, and may flip bits on
1031 * If the extent we found extends past our
1032 * range, we just split and search again. It'll get split
1033 * again the next time though.
1035 * If the extent we found is inside our range, we set the
1036 * desired bit on it.
1038 if (state->start < start) {
1039 prealloc = alloc_extent_state_atomic(prealloc);
1044 err = split_state(tree, state, prealloc, start);
1046 extent_io_tree_panic(tree, err);
1050 if (state->end <= end) {
1051 set_state_bits(tree, state, &bits);
1052 cache_state(state, cached_state);
1053 state = clear_state_bit(tree, state, &clear_bits, 0);
1054 if (last_end == (u64)-1)
1056 start = last_end + 1;
1057 if (start < end && state && state->start == start &&
1064 * | ---- desired range ---- |
1065 * | state | or | state |
1067 * There's a hole, we need to insert something in it and
1068 * ignore the extent we found.
1070 if (state->start > start) {
1072 if (end < last_start)
1075 this_end = last_start - 1;
1077 prealloc = alloc_extent_state_atomic(prealloc);
1084 * Avoid to free 'prealloc' if it can be merged with
1087 err = insert_state(tree, prealloc, start, this_end,
1090 extent_io_tree_panic(tree, err);
1091 cache_state(prealloc, cached_state);
1093 start = this_end + 1;
1097 * | ---- desired range ---- |
1099 * We need to split the extent, and set the bit
1102 if (state->start <= end && state->end > end) {
1103 prealloc = alloc_extent_state_atomic(prealloc);
1109 err = split_state(tree, state, prealloc, end + 1);
1111 extent_io_tree_panic(tree, err);
1113 set_state_bits(tree, prealloc, &bits);
1114 cache_state(prealloc, cached_state);
1115 clear_state_bit(tree, prealloc, &clear_bits, 0);
1123 spin_unlock(&tree->lock);
1125 free_extent_state(prealloc);
1132 spin_unlock(&tree->lock);
1133 if (mask & __GFP_WAIT)
1138 /* wrappers around set/clear extent bit */
1139 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1142 return set_extent_bit(tree, start, end, EXTENT_DIRTY, NULL,
1146 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1147 int bits, gfp_t mask)
1149 return set_extent_bit(tree, start, end, bits, NULL,
1153 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1154 int bits, gfp_t mask)
1156 return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
1159 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
1160 struct extent_state **cached_state, gfp_t mask)
1162 return set_extent_bit(tree, start, end,
1163 EXTENT_DELALLOC | EXTENT_UPTODATE,
1164 NULL, cached_state, mask);
1167 int set_extent_defrag(struct extent_io_tree *tree, u64 start, u64 end,
1168 struct extent_state **cached_state, gfp_t mask)
1170 return set_extent_bit(tree, start, end,
1171 EXTENT_DELALLOC | EXTENT_UPTODATE | EXTENT_DEFRAG,
1172 NULL, cached_state, mask);
1175 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1178 return clear_extent_bit(tree, start, end,
1179 EXTENT_DIRTY | EXTENT_DELALLOC |
1180 EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
1183 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
1186 return set_extent_bit(tree, start, end, EXTENT_NEW, NULL,
1190 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
1191 struct extent_state **cached_state, gfp_t mask)
1193 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0,
1194 cached_state, mask);
1197 int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
1198 struct extent_state **cached_state, gfp_t mask)
1200 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
1201 cached_state, mask);
1205 * either insert or lock state struct between start and end use mask to tell
1206 * us if waiting is desired.
1208 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1209 int bits, struct extent_state **cached_state)
1214 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
1215 EXTENT_LOCKED, &failed_start,
1216 cached_state, GFP_NOFS);
1217 if (err == -EEXIST) {
1218 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1219 start = failed_start;
1222 WARN_ON(start > end);
1227 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1229 return lock_extent_bits(tree, start, end, 0, NULL);
1232 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1237 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1238 &failed_start, NULL, GFP_NOFS);
1239 if (err == -EEXIST) {
1240 if (failed_start > start)
1241 clear_extent_bit(tree, start, failed_start - 1,
1242 EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS);
1248 int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
1249 struct extent_state **cached, gfp_t mask)
1251 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
1255 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1257 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
1262 * helper function to set both pages and extents in the tree writeback
1264 static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1266 unsigned long index = start >> PAGE_CACHE_SHIFT;
1267 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1270 while (index <= end_index) {
1271 page = find_get_page(tree->mapping, index);
1272 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1273 set_page_writeback(page);
1274 page_cache_release(page);
1280 /* find the first state struct with 'bits' set after 'start', and
1281 * return it. tree->lock must be held. NULL will returned if
1282 * nothing was found after 'start'
1284 struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
1285 u64 start, int bits)
1287 struct rb_node *node;
1288 struct extent_state *state;
1291 * this search will find all the extents that end after
1294 node = tree_search(tree, start);
1299 state = rb_entry(node, struct extent_state, rb_node);
1300 if (state->end >= start && (state->state & bits))
1303 node = rb_next(node);
1312 * find the first offset in the io tree with 'bits' set. zero is
1313 * returned if we find something, and *start_ret and *end_ret are
1314 * set to reflect the state struct that was found.
1316 * If nothing was found, 1 is returned. If found something, return 0.
1318 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1319 u64 *start_ret, u64 *end_ret, int bits,
1320 struct extent_state **cached_state)
1322 struct extent_state *state;
1326 spin_lock(&tree->lock);
1327 if (cached_state && *cached_state) {
1328 state = *cached_state;
1329 if (state->end == start - 1 && state->tree) {
1330 n = rb_next(&state->rb_node);
1332 state = rb_entry(n, struct extent_state,
1334 if (state->state & bits)
1338 free_extent_state(*cached_state);
1339 *cached_state = NULL;
1342 free_extent_state(*cached_state);
1343 *cached_state = NULL;
1346 state = find_first_extent_bit_state(tree, start, bits);
1349 cache_state(state, cached_state);
1350 *start_ret = state->start;
1351 *end_ret = state->end;
1355 spin_unlock(&tree->lock);
1360 * find a contiguous range of bytes in the file marked as delalloc, not
1361 * more than 'max_bytes'. start and end are used to return the range,
1363 * 1 is returned if we find something, 0 if nothing was in the tree
1365 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1366 u64 *start, u64 *end, u64 max_bytes,
1367 struct extent_state **cached_state)
1369 struct rb_node *node;
1370 struct extent_state *state;
1371 u64 cur_start = *start;
1373 u64 total_bytes = 0;
1375 spin_lock(&tree->lock);
1378 * this search will find all the extents that end after
1381 node = tree_search(tree, cur_start);
1389 state = rb_entry(node, struct extent_state, rb_node);
1390 if (found && (state->start != cur_start ||
1391 (state->state & EXTENT_BOUNDARY))) {
1394 if (!(state->state & EXTENT_DELALLOC)) {
1400 *start = state->start;
1401 *cached_state = state;
1402 atomic_inc(&state->refs);
1406 cur_start = state->end + 1;
1407 node = rb_next(node);
1410 total_bytes += state->end - state->start + 1;
1411 if (total_bytes >= max_bytes)
1415 spin_unlock(&tree->lock);
1419 static noinline void __unlock_for_delalloc(struct inode *inode,
1420 struct page *locked_page,
1424 struct page *pages[16];
1425 unsigned long index = start >> PAGE_CACHE_SHIFT;
1426 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1427 unsigned long nr_pages = end_index - index + 1;
1430 if (index == locked_page->index && end_index == index)
1433 while (nr_pages > 0) {
1434 ret = find_get_pages_contig(inode->i_mapping, index,
1435 min_t(unsigned long, nr_pages,
1436 ARRAY_SIZE(pages)), pages);
1437 for (i = 0; i < ret; i++) {
1438 if (pages[i] != locked_page)
1439 unlock_page(pages[i]);
1440 page_cache_release(pages[i]);
1448 static noinline int lock_delalloc_pages(struct inode *inode,
1449 struct page *locked_page,
1453 unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
1454 unsigned long start_index = index;
1455 unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
1456 unsigned long pages_locked = 0;
1457 struct page *pages[16];
1458 unsigned long nrpages;
1462 /* the caller is responsible for locking the start index */
1463 if (index == locked_page->index && index == end_index)
1466 /* skip the page at the start index */
1467 nrpages = end_index - index + 1;
1468 while (nrpages > 0) {
1469 ret = find_get_pages_contig(inode->i_mapping, index,
1470 min_t(unsigned long,
1471 nrpages, ARRAY_SIZE(pages)), pages);
1476 /* now we have an array of pages, lock them all */
1477 for (i = 0; i < ret; i++) {
1479 * the caller is taking responsibility for
1482 if (pages[i] != locked_page) {
1483 lock_page(pages[i]);
1484 if (!PageDirty(pages[i]) ||
1485 pages[i]->mapping != inode->i_mapping) {
1487 unlock_page(pages[i]);
1488 page_cache_release(pages[i]);
1492 page_cache_release(pages[i]);
1501 if (ret && pages_locked) {
1502 __unlock_for_delalloc(inode, locked_page,
1504 ((u64)(start_index + pages_locked - 1)) <<
1511 * find a contiguous range of bytes in the file marked as delalloc, not
1512 * more than 'max_bytes'. start and end are used to return the range,
1514 * 1 is returned if we find something, 0 if nothing was in the tree
1516 static noinline u64 find_lock_delalloc_range(struct inode *inode,
1517 struct extent_io_tree *tree,
1518 struct page *locked_page,
1519 u64 *start, u64 *end,
1525 struct extent_state *cached_state = NULL;
1530 /* step one, find a bunch of delalloc bytes starting at start */
1531 delalloc_start = *start;
1533 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1534 max_bytes, &cached_state);
1535 if (!found || delalloc_end <= *start) {
1536 *start = delalloc_start;
1537 *end = delalloc_end;
1538 free_extent_state(cached_state);
1543 * start comes from the offset of locked_page. We have to lock
1544 * pages in order, so we can't process delalloc bytes before
1547 if (delalloc_start < *start)
1548 delalloc_start = *start;
1551 * make sure to limit the number of pages we try to lock down
1554 if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1555 delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
1557 /* step two, lock all the pages after the page that has start */
1558 ret = lock_delalloc_pages(inode, locked_page,
1559 delalloc_start, delalloc_end);
1560 if (ret == -EAGAIN) {
1561 /* some of the pages are gone, lets avoid looping by
1562 * shortening the size of the delalloc range we're searching
1564 free_extent_state(cached_state);
1566 unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
1567 max_bytes = PAGE_CACHE_SIZE - offset;
1575 BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
1577 /* step three, lock the state bits for the whole range */
1578 lock_extent_bits(tree, delalloc_start, delalloc_end, 0, &cached_state);
1580 /* then test to make sure it is all still delalloc */
1581 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1582 EXTENT_DELALLOC, 1, cached_state);
1584 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1585 &cached_state, GFP_NOFS);
1586 __unlock_for_delalloc(inode, locked_page,
1587 delalloc_start, delalloc_end);
1591 free_extent_state(cached_state);
1592 *start = delalloc_start;
1593 *end = delalloc_end;
1598 int extent_clear_unlock_delalloc(struct inode *inode,
1599 struct extent_io_tree *tree,
1600 u64 start, u64 end, struct page *locked_page,
1604 struct page *pages[16];
1605 unsigned long index = start >> PAGE_CACHE_SHIFT;
1606 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1607 unsigned long nr_pages = end_index - index + 1;
1611 if (op & EXTENT_CLEAR_UNLOCK)
1612 clear_bits |= EXTENT_LOCKED;
1613 if (op & EXTENT_CLEAR_DIRTY)
1614 clear_bits |= EXTENT_DIRTY;
1616 if (op & EXTENT_CLEAR_DELALLOC)
1617 clear_bits |= EXTENT_DELALLOC;
1619 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1620 if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
1621 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
1622 EXTENT_SET_PRIVATE2)))
1625 while (nr_pages > 0) {
1626 ret = find_get_pages_contig(inode->i_mapping, index,
1627 min_t(unsigned long,
1628 nr_pages, ARRAY_SIZE(pages)), pages);
1629 for (i = 0; i < ret; i++) {
1631 if (op & EXTENT_SET_PRIVATE2)
1632 SetPagePrivate2(pages[i]);
1634 if (pages[i] == locked_page) {
1635 page_cache_release(pages[i]);
1638 if (op & EXTENT_CLEAR_DIRTY)
1639 clear_page_dirty_for_io(pages[i]);
1640 if (op & EXTENT_SET_WRITEBACK)
1641 set_page_writeback(pages[i]);
1642 if (op & EXTENT_END_WRITEBACK)
1643 end_page_writeback(pages[i]);
1644 if (op & EXTENT_CLEAR_UNLOCK_PAGE)
1645 unlock_page(pages[i]);
1646 page_cache_release(pages[i]);
1656 * count the number of bytes in the tree that have a given bit(s)
1657 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1658 * cached. The total number found is returned.
1660 u64 count_range_bits(struct extent_io_tree *tree,
1661 u64 *start, u64 search_end, u64 max_bytes,
1662 unsigned long bits, int contig)
1664 struct rb_node *node;
1665 struct extent_state *state;
1666 u64 cur_start = *start;
1667 u64 total_bytes = 0;
1671 if (search_end <= cur_start) {
1676 spin_lock(&tree->lock);
1677 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1678 total_bytes = tree->dirty_bytes;
1682 * this search will find all the extents that end after
1685 node = tree_search(tree, cur_start);
1690 state = rb_entry(node, struct extent_state, rb_node);
1691 if (state->start > search_end)
1693 if (contig && found && state->start > last + 1)
1695 if (state->end >= cur_start && (state->state & bits) == bits) {
1696 total_bytes += min(search_end, state->end) + 1 -
1697 max(cur_start, state->start);
1698 if (total_bytes >= max_bytes)
1701 *start = max(cur_start, state->start);
1705 } else if (contig && found) {
1708 node = rb_next(node);
1713 spin_unlock(&tree->lock);
1718 * set the private field for a given byte offset in the tree. If there isn't
1719 * an extent_state there already, this does nothing.
1721 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1723 struct rb_node *node;
1724 struct extent_state *state;
1727 spin_lock(&tree->lock);
1729 * this search will find all the extents that end after
1732 node = tree_search(tree, start);
1737 state = rb_entry(node, struct extent_state, rb_node);
1738 if (state->start != start) {
1742 state->private = private;
1744 spin_unlock(&tree->lock);
1748 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1750 struct rb_node *node;
1751 struct extent_state *state;
1754 spin_lock(&tree->lock);
1756 * this search will find all the extents that end after
1759 node = tree_search(tree, start);
1764 state = rb_entry(node, struct extent_state, rb_node);
1765 if (state->start != start) {
1769 *private = state->private;
1771 spin_unlock(&tree->lock);
1776 * searches a range in the state tree for a given mask.
1777 * If 'filled' == 1, this returns 1 only if every extent in the tree
1778 * has the bits set. Otherwise, 1 is returned if any bit in the
1779 * range is found set.
1781 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1782 int bits, int filled, struct extent_state *cached)
1784 struct extent_state *state = NULL;
1785 struct rb_node *node;
1788 spin_lock(&tree->lock);
1789 if (cached && cached->tree && cached->start <= start &&
1790 cached->end > start)
1791 node = &cached->rb_node;
1793 node = tree_search(tree, start);
1794 while (node && start <= end) {
1795 state = rb_entry(node, struct extent_state, rb_node);
1797 if (filled && state->start > start) {
1802 if (state->start > end)
1805 if (state->state & bits) {
1809 } else if (filled) {
1814 if (state->end == (u64)-1)
1817 start = state->end + 1;
1820 node = rb_next(node);
1827 spin_unlock(&tree->lock);
1832 * helper function to set a given page up to date if all the
1833 * extents in the tree for that page are up to date
1835 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
1837 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1838 u64 end = start + PAGE_CACHE_SIZE - 1;
1839 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1840 SetPageUptodate(page);
1844 * helper function to unlock a page if all the extents in the tree
1845 * for that page are unlocked
1847 static void check_page_locked(struct extent_io_tree *tree, struct page *page)
1849 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1850 u64 end = start + PAGE_CACHE_SIZE - 1;
1851 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
1856 * helper function to end page writeback if all the extents
1857 * in the tree for that page are done with writeback
1859 static void check_page_writeback(struct extent_io_tree *tree,
1862 end_page_writeback(page);
1866 * When IO fails, either with EIO or csum verification fails, we
1867 * try other mirrors that might have a good copy of the data. This
1868 * io_failure_record is used to record state as we go through all the
1869 * mirrors. If another mirror has good data, the page is set up to date
1870 * and things continue. If a good mirror can't be found, the original
1871 * bio end_io callback is called to indicate things have failed.
1873 struct io_failure_record {
1878 unsigned long bio_flags;
1884 static int free_io_failure(struct inode *inode, struct io_failure_record *rec,
1889 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1891 set_state_private(failure_tree, rec->start, 0);
1892 ret = clear_extent_bits(failure_tree, rec->start,
1893 rec->start + rec->len - 1,
1894 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
1899 ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
1900 rec->start + rec->len - 1,
1901 EXTENT_DAMAGED, GFP_NOFS);
1910 static void repair_io_failure_callback(struct bio *bio, int err)
1912 complete(bio->bi_private);
1916 * this bypasses the standard btrfs submit functions deliberately, as
1917 * the standard behavior is to write all copies in a raid setup. here we only
1918 * want to write the one bad copy. so we do the mapping for ourselves and issue
1919 * submit_bio directly.
1920 * to avoid any synchonization issues, wait for the data after writing, which
1921 * actually prevents the read that triggered the error from finishing.
1922 * currently, there can be no more than two copies of every data bit. thus,
1923 * exactly one rewrite is required.
1925 int repair_io_failure(struct btrfs_mapping_tree *map_tree, u64 start,
1926 u64 length, u64 logical, struct page *page,
1930 struct btrfs_device *dev;
1931 DECLARE_COMPLETION_ONSTACK(compl);
1934 struct btrfs_bio *bbio = NULL;
1937 BUG_ON(!mirror_num);
1939 bio = bio_alloc(GFP_NOFS, 1);
1942 bio->bi_private = &compl;
1943 bio->bi_end_io = repair_io_failure_callback;
1945 map_length = length;
1947 ret = btrfs_map_block(map_tree, WRITE, logical,
1948 &map_length, &bbio, mirror_num);
1953 BUG_ON(mirror_num != bbio->mirror_num);
1954 sector = bbio->stripes[mirror_num-1].physical >> 9;
1955 bio->bi_sector = sector;
1956 dev = bbio->stripes[mirror_num-1].dev;
1958 if (!dev || !dev->bdev || !dev->writeable) {
1962 bio->bi_bdev = dev->bdev;
1963 bio_add_page(bio, page, length, start-page_offset(page));
1964 btrfsic_submit_bio(WRITE_SYNC, bio);
1965 wait_for_completion(&compl);
1967 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
1968 /* try to remap that extent elsewhere? */
1970 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
1974 printk_ratelimited_in_rcu(KERN_INFO "btrfs read error corrected: ino %lu off %llu "
1975 "(dev %s sector %llu)\n", page->mapping->host->i_ino,
1976 start, rcu_str_deref(dev->name), sector);
1982 int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb,
1985 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
1986 u64 start = eb->start;
1987 unsigned long i, num_pages = num_extent_pages(eb->start, eb->len);
1990 for (i = 0; i < num_pages; i++) {
1991 struct page *p = extent_buffer_page(eb, i);
1992 ret = repair_io_failure(map_tree, start, PAGE_CACHE_SIZE,
1993 start, p, mirror_num);
1996 start += PAGE_CACHE_SIZE;
2003 * each time an IO finishes, we do a fast check in the IO failure tree
2004 * to see if we need to process or clean up an io_failure_record
2006 static int clean_io_failure(u64 start, struct page *page)
2009 u64 private_failure;
2010 struct io_failure_record *failrec;
2011 struct btrfs_mapping_tree *map_tree;
2012 struct extent_state *state;
2016 struct inode *inode = page->mapping->host;
2019 ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
2020 (u64)-1, 1, EXTENT_DIRTY, 0);
2024 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree, start,
2029 failrec = (struct io_failure_record *)(unsigned long) private_failure;
2030 BUG_ON(!failrec->this_mirror);
2032 if (failrec->in_validation) {
2033 /* there was no real error, just free the record */
2034 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2040 spin_lock(&BTRFS_I(inode)->io_tree.lock);
2041 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
2044 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
2046 if (state && state->start == failrec->start) {
2047 map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree;
2048 num_copies = btrfs_num_copies(map_tree, failrec->logical,
2050 if (num_copies > 1) {
2051 ret = repair_io_failure(map_tree, start, failrec->len,
2052 failrec->logical, page,
2053 failrec->failed_mirror);
2060 ret = free_io_failure(inode, failrec, did_repair);
2066 * this is a generic handler for readpage errors (default
2067 * readpage_io_failed_hook). if other copies exist, read those and write back
2068 * good data to the failed position. does not investigate in remapping the
2069 * failed extent elsewhere, hoping the device will be smart enough to do this as
2073 static int bio_readpage_error(struct bio *failed_bio, struct page *page,
2074 u64 start, u64 end, int failed_mirror,
2075 struct extent_state *state)
2077 struct io_failure_record *failrec = NULL;
2079 struct extent_map *em;
2080 struct inode *inode = page->mapping->host;
2081 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2082 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2083 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2090 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
2092 ret = get_state_private(failure_tree, start, &private);
2094 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2097 failrec->start = start;
2098 failrec->len = end - start + 1;
2099 failrec->this_mirror = 0;
2100 failrec->bio_flags = 0;
2101 failrec->in_validation = 0;
2103 read_lock(&em_tree->lock);
2104 em = lookup_extent_mapping(em_tree, start, failrec->len);
2106 read_unlock(&em_tree->lock);
2111 if (em->start > start || em->start + em->len < start) {
2112 free_extent_map(em);
2115 read_unlock(&em_tree->lock);
2121 logical = start - em->start;
2122 logical = em->block_start + logical;
2123 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2124 logical = em->block_start;
2125 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2126 extent_set_compress_type(&failrec->bio_flags,
2129 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2130 "len=%llu\n", logical, start, failrec->len);
2131 failrec->logical = logical;
2132 free_extent_map(em);
2134 /* set the bits in the private failure tree */
2135 ret = set_extent_bits(failure_tree, start, end,
2136 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
2138 ret = set_state_private(failure_tree, start,
2139 (u64)(unsigned long)failrec);
2140 /* set the bits in the inode's tree */
2142 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED,
2149 failrec = (struct io_failure_record *)(unsigned long)private;
2150 pr_debug("bio_readpage_error: (found) logical=%llu, "
2151 "start=%llu, len=%llu, validation=%d\n",
2152 failrec->logical, failrec->start, failrec->len,
2153 failrec->in_validation);
2155 * when data can be on disk more than twice, add to failrec here
2156 * (e.g. with a list for failed_mirror) to make
2157 * clean_io_failure() clean all those errors at once.
2160 num_copies = btrfs_num_copies(
2161 &BTRFS_I(inode)->root->fs_info->mapping_tree,
2162 failrec->logical, failrec->len);
2163 if (num_copies == 1) {
2165 * we only have a single copy of the data, so don't bother with
2166 * all the retry and error correction code that follows. no
2167 * matter what the error is, it is very likely to persist.
2169 pr_debug("bio_readpage_error: cannot repair, num_copies == 1. "
2170 "state=%p, num_copies=%d, next_mirror %d, "
2171 "failed_mirror %d\n", state, num_copies,
2172 failrec->this_mirror, failed_mirror);
2173 free_io_failure(inode, failrec, 0);
2178 spin_lock(&tree->lock);
2179 state = find_first_extent_bit_state(tree, failrec->start,
2181 if (state && state->start != failrec->start)
2183 spin_unlock(&tree->lock);
2187 * there are two premises:
2188 * a) deliver good data to the caller
2189 * b) correct the bad sectors on disk
2191 if (failed_bio->bi_vcnt > 1) {
2193 * to fulfill b), we need to know the exact failing sectors, as
2194 * we don't want to rewrite any more than the failed ones. thus,
2195 * we need separate read requests for the failed bio
2197 * if the following BUG_ON triggers, our validation request got
2198 * merged. we need separate requests for our algorithm to work.
2200 BUG_ON(failrec->in_validation);
2201 failrec->in_validation = 1;
2202 failrec->this_mirror = failed_mirror;
2203 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
2206 * we're ready to fulfill a) and b) alongside. get a good copy
2207 * of the failed sector and if we succeed, we have setup
2208 * everything for repair_io_failure to do the rest for us.
2210 if (failrec->in_validation) {
2211 BUG_ON(failrec->this_mirror != failed_mirror);
2212 failrec->in_validation = 0;
2213 failrec->this_mirror = 0;
2215 failrec->failed_mirror = failed_mirror;
2216 failrec->this_mirror++;
2217 if (failrec->this_mirror == failed_mirror)
2218 failrec->this_mirror++;
2219 read_mode = READ_SYNC;
2222 if (!state || failrec->this_mirror > num_copies) {
2223 pr_debug("bio_readpage_error: (fail) state=%p, num_copies=%d, "
2224 "next_mirror %d, failed_mirror %d\n", state,
2225 num_copies, failrec->this_mirror, failed_mirror);
2226 free_io_failure(inode, failrec, 0);
2230 bio = bio_alloc(GFP_NOFS, 1);
2232 free_io_failure(inode, failrec, 0);
2235 bio->bi_private = state;
2236 bio->bi_end_io = failed_bio->bi_end_io;
2237 bio->bi_sector = failrec->logical >> 9;
2238 bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
2241 bio_add_page(bio, page, failrec->len, start - page_offset(page));
2243 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2244 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode,
2245 failrec->this_mirror, num_copies, failrec->in_validation);
2247 ret = tree->ops->submit_bio_hook(inode, read_mode, bio,
2248 failrec->this_mirror,
2249 failrec->bio_flags, 0);
2253 /* lots and lots of room for performance fixes in the end_bio funcs */
2255 int end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2257 int uptodate = (err == 0);
2258 struct extent_io_tree *tree;
2261 tree = &BTRFS_I(page->mapping->host)->io_tree;
2263 if (tree->ops && tree->ops->writepage_end_io_hook) {
2264 ret = tree->ops->writepage_end_io_hook(page, start,
2265 end, NULL, uptodate);
2271 ClearPageUptodate(page);
2278 * after a writepage IO is done, we need to:
2279 * clear the uptodate bits on error
2280 * clear the writeback bits in the extent tree for this IO
2281 * end_page_writeback if the page has no more pending IO
2283 * Scheduling is not allowed, so the extent state tree is expected
2284 * to have one and only one object corresponding to this IO.
2286 static void end_bio_extent_writepage(struct bio *bio, int err)
2288 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2289 struct extent_io_tree *tree;
2295 struct page *page = bvec->bv_page;
2296 tree = &BTRFS_I(page->mapping->host)->io_tree;
2298 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
2300 end = start + bvec->bv_len - 1;
2302 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
2307 if (--bvec >= bio->bi_io_vec)
2308 prefetchw(&bvec->bv_page->flags);
2310 if (end_extent_writepage(page, err, start, end))
2314 end_page_writeback(page);
2316 check_page_writeback(tree, page);
2317 } while (bvec >= bio->bi_io_vec);
2323 * after a readpage IO is done, we need to:
2324 * clear the uptodate bits on error
2325 * set the uptodate bits if things worked
2326 * set the page up to date if all extents in the tree are uptodate
2327 * clear the lock bit in the extent tree
2328 * unlock the page if there are no other extents locked for it
2330 * Scheduling is not allowed, so the extent state tree is expected
2331 * to have one and only one object corresponding to this IO.
2333 static void end_bio_extent_readpage(struct bio *bio, int err)
2335 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
2336 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
2337 struct bio_vec *bvec = bio->bi_io_vec;
2338 struct extent_io_tree *tree;
2349 struct page *page = bvec->bv_page;
2350 struct extent_state *cached = NULL;
2351 struct extent_state *state;
2353 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2354 "mirror=%ld\n", (u64)bio->bi_sector, err,
2355 (long int)bio->bi_bdev);
2356 tree = &BTRFS_I(page->mapping->host)->io_tree;
2358 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
2360 end = start + bvec->bv_len - 1;
2362 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
2367 if (++bvec <= bvec_end)
2368 prefetchw(&bvec->bv_page->flags);
2370 spin_lock(&tree->lock);
2371 state = find_first_extent_bit_state(tree, start, EXTENT_LOCKED);
2372 if (state && state->start == start) {
2374 * take a reference on the state, unlock will drop
2377 cache_state(state, &cached);
2379 spin_unlock(&tree->lock);
2381 mirror = (int)(unsigned long)bio->bi_bdev;
2382 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
2383 ret = tree->ops->readpage_end_io_hook(page, start, end,
2388 clean_io_failure(start, page);
2391 if (!uptodate && tree->ops && tree->ops->readpage_io_failed_hook) {
2392 ret = tree->ops->readpage_io_failed_hook(page, mirror);
2394 test_bit(BIO_UPTODATE, &bio->bi_flags))
2396 } else if (!uptodate) {
2398 * The generic bio_readpage_error handles errors the
2399 * following way: If possible, new read requests are
2400 * created and submitted and will end up in
2401 * end_bio_extent_readpage as well (if we're lucky, not
2402 * in the !uptodate case). In that case it returns 0 and
2403 * we just go on with the next page in our bio. If it
2404 * can't handle the error it will return -EIO and we
2405 * remain responsible for that page.
2407 ret = bio_readpage_error(bio, page, start, end, mirror, NULL);
2410 test_bit(BIO_UPTODATE, &bio->bi_flags);
2413 uncache_state(&cached);
2418 if (uptodate && tree->track_uptodate) {
2419 set_extent_uptodate(tree, start, end, &cached,
2422 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2426 SetPageUptodate(page);
2428 ClearPageUptodate(page);
2434 check_page_uptodate(tree, page);
2436 ClearPageUptodate(page);
2439 check_page_locked(tree, page);
2441 } while (bvec <= bvec_end);
2447 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2452 bio = bio_alloc(gfp_flags, nr_vecs);
2454 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2455 while (!bio && (nr_vecs /= 2))
2456 bio = bio_alloc(gfp_flags, nr_vecs);
2461 bio->bi_bdev = bdev;
2462 bio->bi_sector = first_sector;
2468 * Since writes are async, they will only return -ENOMEM.
2469 * Reads can return the full range of I/O error conditions.
2471 static int __must_check submit_one_bio(int rw, struct bio *bio,
2472 int mirror_num, unsigned long bio_flags)
2475 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2476 struct page *page = bvec->bv_page;
2477 struct extent_io_tree *tree = bio->bi_private;
2480 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
2482 bio->bi_private = NULL;
2486 if (tree->ops && tree->ops->submit_bio_hook)
2487 ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
2488 mirror_num, bio_flags, start);
2490 btrfsic_submit_bio(rw, bio);
2492 if (bio_flagged(bio, BIO_EOPNOTSUPP))
2498 static int merge_bio(struct extent_io_tree *tree, struct page *page,
2499 unsigned long offset, size_t size, struct bio *bio,
2500 unsigned long bio_flags)
2503 if (tree->ops && tree->ops->merge_bio_hook)
2504 ret = tree->ops->merge_bio_hook(page, offset, size, bio,
2511 static int submit_extent_page(int rw, struct extent_io_tree *tree,
2512 struct page *page, sector_t sector,
2513 size_t size, unsigned long offset,
2514 struct block_device *bdev,
2515 struct bio **bio_ret,
2516 unsigned long max_pages,
2517 bio_end_io_t end_io_func,
2519 unsigned long prev_bio_flags,
2520 unsigned long bio_flags)
2526 int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
2527 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2528 size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
2530 if (bio_ret && *bio_ret) {
2533 contig = bio->bi_sector == sector;
2535 contig = bio->bi_sector + (bio->bi_size >> 9) ==
2538 if (prev_bio_flags != bio_flags || !contig ||
2539 merge_bio(tree, page, offset, page_size, bio, bio_flags) ||
2540 bio_add_page(bio, page, page_size, offset) < page_size) {
2541 ret = submit_one_bio(rw, bio, mirror_num,
2550 if (this_compressed)
2553 nr = bio_get_nr_vecs(bdev);
2555 bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
2559 bio_add_page(bio, page, page_size, offset);
2560 bio->bi_end_io = end_io_func;
2561 bio->bi_private = tree;
2566 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
2571 void attach_extent_buffer_page(struct extent_buffer *eb, struct page *page)
2573 if (!PagePrivate(page)) {
2574 SetPagePrivate(page);
2575 page_cache_get(page);
2576 set_page_private(page, (unsigned long)eb);
2578 WARN_ON(page->private != (unsigned long)eb);
2582 void set_page_extent_mapped(struct page *page)
2584 if (!PagePrivate(page)) {
2585 SetPagePrivate(page);
2586 page_cache_get(page);
2587 set_page_private(page, EXTENT_PAGE_PRIVATE);
2592 * basic readpage implementation. Locked extent state structs are inserted
2593 * into the tree that are removed when the IO is done (by the end_io
2595 * XXX JDM: This needs looking at to ensure proper page locking
2597 static int __extent_read_full_page(struct extent_io_tree *tree,
2599 get_extent_t *get_extent,
2600 struct bio **bio, int mirror_num,
2601 unsigned long *bio_flags)
2603 struct inode *inode = page->mapping->host;
2604 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2605 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2609 u64 last_byte = i_size_read(inode);
2613 struct extent_map *em;
2614 struct block_device *bdev;
2615 struct btrfs_ordered_extent *ordered;
2618 size_t pg_offset = 0;
2620 size_t disk_io_size;
2621 size_t blocksize = inode->i_sb->s_blocksize;
2622 unsigned long this_bio_flag = 0;
2624 set_page_extent_mapped(page);
2626 if (!PageUptodate(page)) {
2627 if (cleancache_get_page(page) == 0) {
2628 BUG_ON(blocksize != PAGE_SIZE);
2635 lock_extent(tree, start, end);
2636 ordered = btrfs_lookup_ordered_extent(inode, start);
2639 unlock_extent(tree, start, end);
2640 btrfs_start_ordered_extent(inode, ordered, 1);
2641 btrfs_put_ordered_extent(ordered);
2644 if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
2646 size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
2649 iosize = PAGE_CACHE_SIZE - zero_offset;
2650 userpage = kmap_atomic(page);
2651 memset(userpage + zero_offset, 0, iosize);
2652 flush_dcache_page(page);
2653 kunmap_atomic(userpage);
2656 while (cur <= end) {
2657 if (cur >= last_byte) {
2659 struct extent_state *cached = NULL;
2661 iosize = PAGE_CACHE_SIZE - pg_offset;
2662 userpage = kmap_atomic(page);
2663 memset(userpage + pg_offset, 0, iosize);
2664 flush_dcache_page(page);
2665 kunmap_atomic(userpage);
2666 set_extent_uptodate(tree, cur, cur + iosize - 1,
2668 unlock_extent_cached(tree, cur, cur + iosize - 1,
2672 em = get_extent(inode, page, pg_offset, cur,
2674 if (IS_ERR_OR_NULL(em)) {
2676 unlock_extent(tree, cur, end);
2679 extent_offset = cur - em->start;
2680 BUG_ON(extent_map_end(em) <= cur);
2683 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2684 this_bio_flag = EXTENT_BIO_COMPRESSED;
2685 extent_set_compress_type(&this_bio_flag,
2689 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2690 cur_end = min(extent_map_end(em) - 1, end);
2691 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2692 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2693 disk_io_size = em->block_len;
2694 sector = em->block_start >> 9;
2696 sector = (em->block_start + extent_offset) >> 9;
2697 disk_io_size = iosize;
2700 block_start = em->block_start;
2701 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2702 block_start = EXTENT_MAP_HOLE;
2703 free_extent_map(em);
2706 /* we've found a hole, just zero and go on */
2707 if (block_start == EXTENT_MAP_HOLE) {
2709 struct extent_state *cached = NULL;
2711 userpage = kmap_atomic(page);
2712 memset(userpage + pg_offset, 0, iosize);
2713 flush_dcache_page(page);
2714 kunmap_atomic(userpage);
2716 set_extent_uptodate(tree, cur, cur + iosize - 1,
2718 unlock_extent_cached(tree, cur, cur + iosize - 1,
2721 pg_offset += iosize;
2724 /* the get_extent function already copied into the page */
2725 if (test_range_bit(tree, cur, cur_end,
2726 EXTENT_UPTODATE, 1, NULL)) {
2727 check_page_uptodate(tree, page);
2728 unlock_extent(tree, cur, cur + iosize - 1);
2730 pg_offset += iosize;
2733 /* we have an inline extent but it didn't get marked up
2734 * to date. Error out
2736 if (block_start == EXTENT_MAP_INLINE) {
2738 unlock_extent(tree, cur, cur + iosize - 1);
2740 pg_offset += iosize;
2745 if (tree->ops && tree->ops->readpage_io_hook) {
2746 ret = tree->ops->readpage_io_hook(page, cur,
2750 unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
2752 ret = submit_extent_page(READ, tree, page,
2753 sector, disk_io_size, pg_offset,
2755 end_bio_extent_readpage, mirror_num,
2760 *bio_flags = this_bio_flag;
2765 unlock_extent(tree, cur, cur + iosize - 1);
2768 pg_offset += iosize;
2772 if (!PageError(page))
2773 SetPageUptodate(page);
2779 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
2780 get_extent_t *get_extent, int mirror_num)
2782 struct bio *bio = NULL;
2783 unsigned long bio_flags = 0;
2786 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
2789 ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
2793 static noinline void update_nr_written(struct page *page,
2794 struct writeback_control *wbc,
2795 unsigned long nr_written)
2797 wbc->nr_to_write -= nr_written;
2798 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
2799 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
2800 page->mapping->writeback_index = page->index + nr_written;
2804 * the writepage semantics are similar to regular writepage. extent
2805 * records are inserted to lock ranges in the tree, and as dirty areas
2806 * are found, they are marked writeback. Then the lock bits are removed
2807 * and the end_io handler clears the writeback ranges
2809 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
2812 struct inode *inode = page->mapping->host;
2813 struct extent_page_data *epd = data;
2814 struct extent_io_tree *tree = epd->tree;
2815 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2817 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2821 u64 last_byte = i_size_read(inode);
2825 struct extent_state *cached_state = NULL;
2826 struct extent_map *em;
2827 struct block_device *bdev;
2830 size_t pg_offset = 0;
2832 loff_t i_size = i_size_read(inode);
2833 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
2839 unsigned long nr_written = 0;
2840 bool fill_delalloc = true;
2842 if (wbc->sync_mode == WB_SYNC_ALL)
2843 write_flags = WRITE_SYNC;
2845 write_flags = WRITE;
2847 trace___extent_writepage(page, inode, wbc);
2849 WARN_ON(!PageLocked(page));
2851 ClearPageError(page);
2853 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2854 if (page->index > end_index ||
2855 (page->index == end_index && !pg_offset)) {
2856 page->mapping->a_ops->invalidatepage(page, 0);
2861 if (page->index == end_index) {
2864 userpage = kmap_atomic(page);
2865 memset(userpage + pg_offset, 0,
2866 PAGE_CACHE_SIZE - pg_offset);
2867 kunmap_atomic(userpage);
2868 flush_dcache_page(page);
2872 set_page_extent_mapped(page);
2874 if (!tree->ops || !tree->ops->fill_delalloc)
2875 fill_delalloc = false;
2877 delalloc_start = start;
2880 if (!epd->extent_locked && fill_delalloc) {
2881 u64 delalloc_to_write = 0;
2883 * make sure the wbc mapping index is at least updated
2886 update_nr_written(page, wbc, 0);
2888 while (delalloc_end < page_end) {
2889 nr_delalloc = find_lock_delalloc_range(inode, tree,
2894 if (nr_delalloc == 0) {
2895 delalloc_start = delalloc_end + 1;
2898 ret = tree->ops->fill_delalloc(inode, page,
2903 /* File system has been set read-only */
2909 * delalloc_end is already one less than the total
2910 * length, so we don't subtract one from
2913 delalloc_to_write += (delalloc_end - delalloc_start +
2916 delalloc_start = delalloc_end + 1;
2918 if (wbc->nr_to_write < delalloc_to_write) {
2921 if (delalloc_to_write < thresh * 2)
2922 thresh = delalloc_to_write;
2923 wbc->nr_to_write = min_t(u64, delalloc_to_write,
2927 /* did the fill delalloc function already unlock and start
2933 * we've unlocked the page, so we can't update
2934 * the mapping's writeback index, just update
2937 wbc->nr_to_write -= nr_written;
2941 if (tree->ops && tree->ops->writepage_start_hook) {
2942 ret = tree->ops->writepage_start_hook(page, start,
2945 /* Fixup worker will requeue */
2947 wbc->pages_skipped++;
2949 redirty_page_for_writepage(wbc, page);
2950 update_nr_written(page, wbc, nr_written);
2958 * we don't want to touch the inode after unlocking the page,
2959 * so we update the mapping writeback index now
2961 update_nr_written(page, wbc, nr_written + 1);
2964 if (last_byte <= start) {
2965 if (tree->ops && tree->ops->writepage_end_io_hook)
2966 tree->ops->writepage_end_io_hook(page, start,
2971 blocksize = inode->i_sb->s_blocksize;
2973 while (cur <= end) {
2974 if (cur >= last_byte) {
2975 if (tree->ops && tree->ops->writepage_end_io_hook)
2976 tree->ops->writepage_end_io_hook(page, cur,
2980 em = epd->get_extent(inode, page, pg_offset, cur,
2982 if (IS_ERR_OR_NULL(em)) {
2987 extent_offset = cur - em->start;
2988 BUG_ON(extent_map_end(em) <= cur);
2990 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2991 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2992 sector = (em->block_start + extent_offset) >> 9;
2994 block_start = em->block_start;
2995 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
2996 free_extent_map(em);
3000 * compressed and inline extents are written through other
3003 if (compressed || block_start == EXTENT_MAP_HOLE ||
3004 block_start == EXTENT_MAP_INLINE) {
3006 * end_io notification does not happen here for
3007 * compressed extents
3009 if (!compressed && tree->ops &&
3010 tree->ops->writepage_end_io_hook)
3011 tree->ops->writepage_end_io_hook(page, cur,
3014 else if (compressed) {
3015 /* we don't want to end_page_writeback on
3016 * a compressed extent. this happens
3023 pg_offset += iosize;
3026 /* leave this out until we have a page_mkwrite call */
3027 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
3028 EXTENT_DIRTY, 0, NULL)) {
3030 pg_offset += iosize;
3034 if (tree->ops && tree->ops->writepage_io_hook) {
3035 ret = tree->ops->writepage_io_hook(page, cur,
3043 unsigned long max_nr = end_index + 1;
3045 set_range_writeback(tree, cur, cur + iosize - 1);
3046 if (!PageWriteback(page)) {
3047 printk(KERN_ERR "btrfs warning page %lu not "
3048 "writeback, cur %llu end %llu\n",
3049 page->index, (unsigned long long)cur,
3050 (unsigned long long)end);
3053 ret = submit_extent_page(write_flags, tree, page,
3054 sector, iosize, pg_offset,
3055 bdev, &epd->bio, max_nr,
3056 end_bio_extent_writepage,
3062 pg_offset += iosize;
3067 /* make sure the mapping tag for page dirty gets cleared */
3068 set_page_writeback(page);
3069 end_page_writeback(page);
3075 /* drop our reference on any cached states */
3076 free_extent_state(cached_state);
3080 static int eb_wait(void *word)
3086 static void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3088 wait_on_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK, eb_wait,
3089 TASK_UNINTERRUPTIBLE);
3092 static int lock_extent_buffer_for_io(struct extent_buffer *eb,
3093 struct btrfs_fs_info *fs_info,
3094 struct extent_page_data *epd)
3096 unsigned long i, num_pages;
3100 if (!btrfs_try_tree_write_lock(eb)) {
3102 flush_write_bio(epd);
3103 btrfs_tree_lock(eb);
3106 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3107 btrfs_tree_unlock(eb);
3111 flush_write_bio(epd);
3115 wait_on_extent_buffer_writeback(eb);
3116 btrfs_tree_lock(eb);
3117 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3119 btrfs_tree_unlock(eb);
3124 * We need to do this to prevent races in people who check if the eb is
3125 * under IO since we can end up having no IO bits set for a short period
3128 spin_lock(&eb->refs_lock);
3129 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3130 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3131 spin_unlock(&eb->refs_lock);
3132 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3133 spin_lock(&fs_info->delalloc_lock);
3134 if (fs_info->dirty_metadata_bytes >= eb->len)
3135 fs_info->dirty_metadata_bytes -= eb->len;
3138 spin_unlock(&fs_info->delalloc_lock);
3141 spin_unlock(&eb->refs_lock);
3144 btrfs_tree_unlock(eb);
3149 num_pages = num_extent_pages(eb->start, eb->len);
3150 for (i = 0; i < num_pages; i++) {
3151 struct page *p = extent_buffer_page(eb, i);
3153 if (!trylock_page(p)) {
3155 flush_write_bio(epd);
3165 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3167 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3168 smp_mb__after_clear_bit();
3169 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3172 static void end_bio_extent_buffer_writepage(struct bio *bio, int err)
3174 int uptodate = err == 0;
3175 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
3176 struct extent_buffer *eb;
3180 struct page *page = bvec->bv_page;
3183 eb = (struct extent_buffer *)page->private;
3185 done = atomic_dec_and_test(&eb->io_pages);
3187 if (!uptodate || test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) {
3188 set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3189 ClearPageUptodate(page);
3193 end_page_writeback(page);
3198 end_extent_buffer_writeback(eb);
3199 } while (bvec >= bio->bi_io_vec);
3205 static int write_one_eb(struct extent_buffer *eb,
3206 struct btrfs_fs_info *fs_info,
3207 struct writeback_control *wbc,
3208 struct extent_page_data *epd)
3210 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3211 u64 offset = eb->start;
3212 unsigned long i, num_pages;
3213 unsigned long bio_flags = 0;
3214 int rw = (epd->sync_io ? WRITE_SYNC : WRITE);
3217 clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3218 num_pages = num_extent_pages(eb->start, eb->len);
3219 atomic_set(&eb->io_pages, num_pages);
3220 if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
3221 bio_flags = EXTENT_BIO_TREE_LOG;
3223 for (i = 0; i < num_pages; i++) {
3224 struct page *p = extent_buffer_page(eb, i);
3226 clear_page_dirty_for_io(p);
3227 set_page_writeback(p);
3228 ret = submit_extent_page(rw, eb->tree, p, offset >> 9,
3229 PAGE_CACHE_SIZE, 0, bdev, &epd->bio,
3230 -1, end_bio_extent_buffer_writepage,
3231 0, epd->bio_flags, bio_flags);
3232 epd->bio_flags = bio_flags;
3234 set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3236 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3237 end_extent_buffer_writeback(eb);
3241 offset += PAGE_CACHE_SIZE;
3242 update_nr_written(p, wbc, 1);
3246 if (unlikely(ret)) {
3247 for (; i < num_pages; i++) {
3248 struct page *p = extent_buffer_page(eb, i);
3256 int btree_write_cache_pages(struct address_space *mapping,
3257 struct writeback_control *wbc)
3259 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3260 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3261 struct extent_buffer *eb, *prev_eb = NULL;
3262 struct extent_page_data epd = {
3266 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3271 int nr_to_write_done = 0;
3272 struct pagevec pvec;
3275 pgoff_t end; /* Inclusive */
3279 pagevec_init(&pvec, 0);
3280 if (wbc->range_cyclic) {
3281 index = mapping->writeback_index; /* Start from prev offset */
3284 index = wbc->range_start >> PAGE_CACHE_SHIFT;
3285 end = wbc->range_end >> PAGE_CACHE_SHIFT;
3288 if (wbc->sync_mode == WB_SYNC_ALL)
3289 tag = PAGECACHE_TAG_TOWRITE;
3291 tag = PAGECACHE_TAG_DIRTY;
3293 if (wbc->sync_mode == WB_SYNC_ALL)
3294 tag_pages_for_writeback(mapping, index, end);
3295 while (!done && !nr_to_write_done && (index <= end) &&
3296 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3297 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3301 for (i = 0; i < nr_pages; i++) {
3302 struct page *page = pvec.pages[i];
3304 if (!PagePrivate(page))
3307 if (!wbc->range_cyclic && page->index > end) {
3312 spin_lock(&mapping->private_lock);
3313 if (!PagePrivate(page)) {
3314 spin_unlock(&mapping->private_lock);
3318 eb = (struct extent_buffer *)page->private;
3321 * Shouldn't happen and normally this would be a BUG_ON
3322 * but no sense in crashing the users box for something
3323 * we can survive anyway.
3326 spin_unlock(&mapping->private_lock);
3331 if (eb == prev_eb) {
3332 spin_unlock(&mapping->private_lock);
3336 ret = atomic_inc_not_zero(&eb->refs);
3337 spin_unlock(&mapping->private_lock);
3342 ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
3344 free_extent_buffer(eb);
3348 ret = write_one_eb(eb, fs_info, wbc, &epd);
3351 free_extent_buffer(eb);
3354 free_extent_buffer(eb);
3357 * the filesystem may choose to bump up nr_to_write.
3358 * We have to make sure to honor the new nr_to_write
3361 nr_to_write_done = wbc->nr_to_write <= 0;
3363 pagevec_release(&pvec);
3366 if (!scanned && !done) {
3368 * We hit the last page and there is more work to be done: wrap
3369 * back to the start of the file
3375 flush_write_bio(&epd);
3380 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3381 * @mapping: address space structure to write
3382 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3383 * @writepage: function called for each page
3384 * @data: data passed to writepage function
3386 * If a page is already under I/O, write_cache_pages() skips it, even
3387 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3388 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3389 * and msync() need to guarantee that all the data which was dirty at the time
3390 * the call was made get new I/O started against them. If wbc->sync_mode is
3391 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3392 * existing IO to complete.
3394 static int extent_write_cache_pages(struct extent_io_tree *tree,
3395 struct address_space *mapping,
3396 struct writeback_control *wbc,
3397 writepage_t writepage, void *data,
3398 void (*flush_fn)(void *))
3400 struct inode *inode = mapping->host;
3403 int nr_to_write_done = 0;
3404 struct pagevec pvec;
3407 pgoff_t end; /* Inclusive */
3412 * We have to hold onto the inode so that ordered extents can do their
3413 * work when the IO finishes. The alternative to this is failing to add
3414 * an ordered extent if the igrab() fails there and that is a huge pain
3415 * to deal with, so instead just hold onto the inode throughout the
3416 * writepages operation. If it fails here we are freeing up the inode
3417 * anyway and we'd rather not waste our time writing out stuff that is
3418 * going to be truncated anyway.
3423 pagevec_init(&pvec, 0);
3424 if (wbc->range_cyclic) {
3425 index = mapping->writeback_index; /* Start from prev offset */
3428 index = wbc->range_start >> PAGE_CACHE_SHIFT;
3429 end = wbc->range_end >> PAGE_CACHE_SHIFT;
3432 if (wbc->sync_mode == WB_SYNC_ALL)
3433 tag = PAGECACHE_TAG_TOWRITE;
3435 tag = PAGECACHE_TAG_DIRTY;
3437 if (wbc->sync_mode == WB_SYNC_ALL)
3438 tag_pages_for_writeback(mapping, index, end);
3439 while (!done && !nr_to_write_done && (index <= end) &&
3440 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3441 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3445 for (i = 0; i < nr_pages; i++) {
3446 struct page *page = pvec.pages[i];
3449 * At this point we hold neither mapping->tree_lock nor
3450 * lock on the page itself: the page may be truncated or
3451 * invalidated (changing page->mapping to NULL), or even
3452 * swizzled back from swapper_space to tmpfs file
3456 tree->ops->write_cache_pages_lock_hook) {
3457 tree->ops->write_cache_pages_lock_hook(page,
3460 if (!trylock_page(page)) {
3466 if (unlikely(page->mapping != mapping)) {
3471 if (!wbc->range_cyclic && page->index > end) {
3477 if (wbc->sync_mode != WB_SYNC_NONE) {
3478 if (PageWriteback(page))
3480 wait_on_page_writeback(page);
3483 if (PageWriteback(page) ||
3484 !clear_page_dirty_for_io(page)) {
3489 ret = (*writepage)(page, wbc, data);
3491 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
3499 * the filesystem may choose to bump up nr_to_write.
3500 * We have to make sure to honor the new nr_to_write
3503 nr_to_write_done = wbc->nr_to_write <= 0;
3505 pagevec_release(&pvec);
3508 if (!scanned && !done) {
3510 * We hit the last page and there is more work to be done: wrap
3511 * back to the start of the file
3517 btrfs_add_delayed_iput(inode);
3521 static void flush_epd_write_bio(struct extent_page_data *epd)
3530 ret = submit_one_bio(rw, epd->bio, 0, epd->bio_flags);
3531 BUG_ON(ret < 0); /* -ENOMEM */
3536 static noinline void flush_write_bio(void *data)
3538 struct extent_page_data *epd = data;
3539 flush_epd_write_bio(epd);
3542 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
3543 get_extent_t *get_extent,
3544 struct writeback_control *wbc)
3547 struct extent_page_data epd = {
3550 .get_extent = get_extent,
3552 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3556 ret = __extent_writepage(page, wbc, &epd);
3558 flush_epd_write_bio(&epd);
3562 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
3563 u64 start, u64 end, get_extent_t *get_extent,
3567 struct address_space *mapping = inode->i_mapping;
3569 unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
3572 struct extent_page_data epd = {
3575 .get_extent = get_extent,
3577 .sync_io = mode == WB_SYNC_ALL,
3580 struct writeback_control wbc_writepages = {
3582 .nr_to_write = nr_pages * 2,
3583 .range_start = start,
3584 .range_end = end + 1,
3587 while (start <= end) {
3588 page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
3589 if (clear_page_dirty_for_io(page))
3590 ret = __extent_writepage(page, &wbc_writepages, &epd);
3592 if (tree->ops && tree->ops->writepage_end_io_hook)
3593 tree->ops->writepage_end_io_hook(page, start,
3594 start + PAGE_CACHE_SIZE - 1,
3598 page_cache_release(page);
3599 start += PAGE_CACHE_SIZE;
3602 flush_epd_write_bio(&epd);
3606 int extent_writepages(struct extent_io_tree *tree,
3607 struct address_space *mapping,
3608 get_extent_t *get_extent,
3609 struct writeback_control *wbc)
3612 struct extent_page_data epd = {
3615 .get_extent = get_extent,
3617 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3621 ret = extent_write_cache_pages(tree, mapping, wbc,
3622 __extent_writepage, &epd,
3624 flush_epd_write_bio(&epd);
3628 int extent_readpages(struct extent_io_tree *tree,
3629 struct address_space *mapping,
3630 struct list_head *pages, unsigned nr_pages,
3631 get_extent_t get_extent)
3633 struct bio *bio = NULL;
3635 unsigned long bio_flags = 0;
3636 struct page *pagepool[16];
3641 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
3642 page = list_entry(pages->prev, struct page, lru);
3644 prefetchw(&page->flags);
3645 list_del(&page->lru);
3646 if (add_to_page_cache_lru(page, mapping,
3647 page->index, GFP_NOFS)) {
3648 page_cache_release(page);
3652 pagepool[nr++] = page;
3653 if (nr < ARRAY_SIZE(pagepool))
3655 for (i = 0; i < nr; i++) {
3656 __extent_read_full_page(tree, pagepool[i], get_extent,
3657 &bio, 0, &bio_flags);
3658 page_cache_release(pagepool[i]);
3662 for (i = 0; i < nr; i++) {
3663 __extent_read_full_page(tree, pagepool[i], get_extent,
3664 &bio, 0, &bio_flags);
3665 page_cache_release(pagepool[i]);
3668 BUG_ON(!list_empty(pages));
3670 return submit_one_bio(READ, bio, 0, bio_flags);
3675 * basic invalidatepage code, this waits on any locked or writeback
3676 * ranges corresponding to the page, and then deletes any extent state
3677 * records from the tree
3679 int extent_invalidatepage(struct extent_io_tree *tree,
3680 struct page *page, unsigned long offset)
3682 struct extent_state *cached_state = NULL;
3683 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
3684 u64 end = start + PAGE_CACHE_SIZE - 1;
3685 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
3687 start += (offset + blocksize - 1) & ~(blocksize - 1);
3691 lock_extent_bits(tree, start, end, 0, &cached_state);
3692 wait_on_page_writeback(page);
3693 clear_extent_bit(tree, start, end,
3694 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
3695 EXTENT_DO_ACCOUNTING,
3696 1, 1, &cached_state, GFP_NOFS);
3701 * a helper for releasepage, this tests for areas of the page that
3702 * are locked or under IO and drops the related state bits if it is safe
3705 int try_release_extent_state(struct extent_map_tree *map,
3706 struct extent_io_tree *tree, struct page *page,
3709 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
3710 u64 end = start + PAGE_CACHE_SIZE - 1;
3713 if (test_range_bit(tree, start, end,
3714 EXTENT_IOBITS, 0, NULL))
3717 if ((mask & GFP_NOFS) == GFP_NOFS)
3720 * at this point we can safely clear everything except the
3721 * locked bit and the nodatasum bit
3723 ret = clear_extent_bit(tree, start, end,
3724 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
3727 /* if clear_extent_bit failed for enomem reasons,
3728 * we can't allow the release to continue.
3739 * a helper for releasepage. As long as there are no locked extents
3740 * in the range corresponding to the page, both state records and extent
3741 * map records are removed
3743 int try_release_extent_mapping(struct extent_map_tree *map,
3744 struct extent_io_tree *tree, struct page *page,
3747 struct extent_map *em;
3748 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
3749 u64 end = start + PAGE_CACHE_SIZE - 1;
3751 if ((mask & __GFP_WAIT) &&
3752 page->mapping->host->i_size > 16 * 1024 * 1024) {
3754 while (start <= end) {
3755 len = end - start + 1;
3756 write_lock(&map->lock);
3757 em = lookup_extent_mapping(map, start, len);
3759 write_unlock(&map->lock);
3762 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
3763 em->start != start) {
3764 write_unlock(&map->lock);
3765 free_extent_map(em);
3768 if (!test_range_bit(tree, em->start,
3769 extent_map_end(em) - 1,
3770 EXTENT_LOCKED | EXTENT_WRITEBACK,
3772 remove_extent_mapping(map, em);
3773 /* once for the rb tree */
3774 free_extent_map(em);
3776 start = extent_map_end(em);
3777 write_unlock(&map->lock);
3780 free_extent_map(em);
3783 return try_release_extent_state(map, tree, page, mask);
3787 * helper function for fiemap, which doesn't want to see any holes.
3788 * This maps until we find something past 'last'
3790 static struct extent_map *get_extent_skip_holes(struct inode *inode,
3793 get_extent_t *get_extent)
3795 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
3796 struct extent_map *em;
3803 len = last - offset;
3806 len = (len + sectorsize - 1) & ~(sectorsize - 1);
3807 em = get_extent(inode, NULL, 0, offset, len, 0);
3808 if (IS_ERR_OR_NULL(em))
3811 /* if this isn't a hole return it */
3812 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
3813 em->block_start != EXTENT_MAP_HOLE) {
3817 /* this is a hole, advance to the next extent */
3818 offset = extent_map_end(em);
3819 free_extent_map(em);
3826 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3827 __u64 start, __u64 len, get_extent_t *get_extent)
3831 u64 max = start + len;
3835 u64 last_for_get_extent = 0;
3837 u64 isize = i_size_read(inode);
3838 struct btrfs_key found_key;
3839 struct extent_map *em = NULL;
3840 struct extent_state *cached_state = NULL;
3841 struct btrfs_path *path;
3842 struct btrfs_file_extent_item *item;
3847 unsigned long emflags;
3852 path = btrfs_alloc_path();
3855 path->leave_spinning = 1;
3857 start = ALIGN(start, BTRFS_I(inode)->root->sectorsize);
3858 len = ALIGN(len, BTRFS_I(inode)->root->sectorsize);
3861 * lookup the last file extent. We're not using i_size here
3862 * because there might be preallocation past i_size
3864 ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
3865 path, btrfs_ino(inode), -1, 0);
3867 btrfs_free_path(path);
3872 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3873 struct btrfs_file_extent_item);
3874 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
3875 found_type = btrfs_key_type(&found_key);
3877 /* No extents, but there might be delalloc bits */
3878 if (found_key.objectid != btrfs_ino(inode) ||
3879 found_type != BTRFS_EXTENT_DATA_KEY) {
3880 /* have to trust i_size as the end */
3882 last_for_get_extent = isize;
3885 * remember the start of the last extent. There are a
3886 * bunch of different factors that go into the length of the
3887 * extent, so its much less complex to remember where it started
3889 last = found_key.offset;
3890 last_for_get_extent = last + 1;
3892 btrfs_free_path(path);
3895 * we might have some extents allocated but more delalloc past those
3896 * extents. so, we trust isize unless the start of the last extent is
3901 last_for_get_extent = isize;
3904 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
3907 em = get_extent_skip_holes(inode, start, last_for_get_extent,
3917 u64 offset_in_extent;
3919 /* break if the extent we found is outside the range */
3920 if (em->start >= max || extent_map_end(em) < off)
3924 * get_extent may return an extent that starts before our
3925 * requested range. We have to make sure the ranges
3926 * we return to fiemap always move forward and don't
3927 * overlap, so adjust the offsets here
3929 em_start = max(em->start, off);
3932 * record the offset from the start of the extent
3933 * for adjusting the disk offset below
3935 offset_in_extent = em_start - em->start;
3936 em_end = extent_map_end(em);
3937 em_len = em_end - em_start;
3938 emflags = em->flags;
3943 * bump off for our next call to get_extent
3945 off = extent_map_end(em);
3949 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
3951 flags |= FIEMAP_EXTENT_LAST;
3952 } else if (em->block_start == EXTENT_MAP_INLINE) {
3953 flags |= (FIEMAP_EXTENT_DATA_INLINE |
3954 FIEMAP_EXTENT_NOT_ALIGNED);
3955 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
3956 flags |= (FIEMAP_EXTENT_DELALLOC |
3957 FIEMAP_EXTENT_UNKNOWN);
3959 disko = em->block_start + offset_in_extent;
3961 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
3962 flags |= FIEMAP_EXTENT_ENCODED;
3964 free_extent_map(em);
3966 if ((em_start >= last) || em_len == (u64)-1 ||
3967 (last == (u64)-1 && isize <= em_end)) {
3968 flags |= FIEMAP_EXTENT_LAST;
3972 /* now scan forward to see if this is really the last extent. */
3973 em = get_extent_skip_holes(inode, off, last_for_get_extent,
3980 flags |= FIEMAP_EXTENT_LAST;
3983 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
3989 free_extent_map(em);
3991 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len,
3992 &cached_state, GFP_NOFS);
3996 static void __free_extent_buffer(struct extent_buffer *eb)
3999 unsigned long flags;
4000 spin_lock_irqsave(&leak_lock, flags);
4001 list_del(&eb->leak_list);
4002 spin_unlock_irqrestore(&leak_lock, flags);
4004 if (eb->pages && eb->pages != eb->inline_pages)
4006 kmem_cache_free(extent_buffer_cache, eb);
4009 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
4014 struct extent_buffer *eb = NULL;
4016 unsigned long flags;
4019 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
4026 rwlock_init(&eb->lock);
4027 atomic_set(&eb->write_locks, 0);
4028 atomic_set(&eb->read_locks, 0);
4029 atomic_set(&eb->blocking_readers, 0);
4030 atomic_set(&eb->blocking_writers, 0);
4031 atomic_set(&eb->spinning_readers, 0);
4032 atomic_set(&eb->spinning_writers, 0);
4033 eb->lock_nested = 0;
4034 init_waitqueue_head(&eb->write_lock_wq);
4035 init_waitqueue_head(&eb->read_lock_wq);
4038 spin_lock_irqsave(&leak_lock, flags);
4039 list_add(&eb->leak_list, &buffers);
4040 spin_unlock_irqrestore(&leak_lock, flags);
4042 spin_lock_init(&eb->refs_lock);
4043 atomic_set(&eb->refs, 1);
4044 atomic_set(&eb->io_pages, 0);
4046 if (len > MAX_INLINE_EXTENT_BUFFER_SIZE) {
4047 struct page **pages;
4048 int num_pages = (len + PAGE_CACHE_SIZE - 1) >>
4050 pages = kzalloc(num_pages, mask);
4052 __free_extent_buffer(eb);
4057 eb->pages = eb->inline_pages;
4063 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4067 struct extent_buffer *new;
4068 unsigned long num_pages = num_extent_pages(src->start, src->len);
4070 new = __alloc_extent_buffer(NULL, src->start, src->len, GFP_ATOMIC);
4074 for (i = 0; i < num_pages; i++) {
4075 p = alloc_page(GFP_ATOMIC);
4077 attach_extent_buffer_page(new, p);
4078 WARN_ON(PageDirty(p));
4083 copy_extent_buffer(new, src, 0, 0, src->len);
4084 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4085 set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
4090 struct extent_buffer *alloc_dummy_extent_buffer(u64 start, unsigned long len)
4092 struct extent_buffer *eb;
4093 unsigned long num_pages = num_extent_pages(0, len);
4096 eb = __alloc_extent_buffer(NULL, start, len, GFP_ATOMIC);
4100 for (i = 0; i < num_pages; i++) {
4101 eb->pages[i] = alloc_page(GFP_ATOMIC);
4105 set_extent_buffer_uptodate(eb);
4106 btrfs_set_header_nritems(eb, 0);
4107 set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4112 __free_page(eb->pages[i - 1]);
4113 __free_extent_buffer(eb);
4117 static int extent_buffer_under_io(struct extent_buffer *eb)
4119 return (atomic_read(&eb->io_pages) ||
4120 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4121 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4125 * Helper for releasing extent buffer page.
4127 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
4128 unsigned long start_idx)
4130 unsigned long index;
4131 unsigned long num_pages;
4133 int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4135 BUG_ON(extent_buffer_under_io(eb));
4137 num_pages = num_extent_pages(eb->start, eb->len);
4138 index = start_idx + num_pages;
4139 if (start_idx >= index)
4144 page = extent_buffer_page(eb, index);
4145 if (page && mapped) {
4146 spin_lock(&page->mapping->private_lock);
4148 * We do this since we'll remove the pages after we've
4149 * removed the eb from the radix tree, so we could race
4150 * and have this page now attached to the new eb. So
4151 * only clear page_private if it's still connected to
4154 if (PagePrivate(page) &&
4155 page->private == (unsigned long)eb) {
4156 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4157 BUG_ON(PageDirty(page));
4158 BUG_ON(PageWriteback(page));
4160 * We need to make sure we haven't be attached
4163 ClearPagePrivate(page);
4164 set_page_private(page, 0);
4165 /* One for the page private */
4166 page_cache_release(page);
4168 spin_unlock(&page->mapping->private_lock);
4172 /* One for when we alloced the page */
4173 page_cache_release(page);
4175 } while (index != start_idx);
4179 * Helper for releasing the extent buffer.
4181 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4183 btrfs_release_extent_buffer_page(eb, 0);
4184 __free_extent_buffer(eb);
4187 static void check_buffer_tree_ref(struct extent_buffer *eb)
4189 /* the ref bit is tricky. We have to make sure it is set
4190 * if we have the buffer dirty. Otherwise the
4191 * code to free a buffer can end up dropping a dirty
4194 * Once the ref bit is set, it won't go away while the
4195 * buffer is dirty or in writeback, and it also won't
4196 * go away while we have the reference count on the
4199 * We can't just set the ref bit without bumping the
4200 * ref on the eb because free_extent_buffer might
4201 * see the ref bit and try to clear it. If this happens
4202 * free_extent_buffer might end up dropping our original
4203 * ref by mistake and freeing the page before we are able
4204 * to add one more ref.
4206 * So bump the ref count first, then set the bit. If someone
4207 * beat us to it, drop the ref we added.
4209 spin_lock(&eb->refs_lock);
4210 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4211 atomic_inc(&eb->refs);
4212 spin_unlock(&eb->refs_lock);
4215 static void mark_extent_buffer_accessed(struct extent_buffer *eb)
4217 unsigned long num_pages, i;
4219 check_buffer_tree_ref(eb);
4221 num_pages = num_extent_pages(eb->start, eb->len);
4222 for (i = 0; i < num_pages; i++) {
4223 struct page *p = extent_buffer_page(eb, i);
4224 mark_page_accessed(p);
4228 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
4229 u64 start, unsigned long len)
4231 unsigned long num_pages = num_extent_pages(start, len);
4233 unsigned long index = start >> PAGE_CACHE_SHIFT;
4234 struct extent_buffer *eb;
4235 struct extent_buffer *exists = NULL;
4237 struct address_space *mapping = tree->mapping;
4242 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4243 if (eb && atomic_inc_not_zero(&eb->refs)) {
4245 mark_extent_buffer_accessed(eb);
4250 eb = __alloc_extent_buffer(tree, start, len, GFP_NOFS);
4254 for (i = 0; i < num_pages; i++, index++) {
4255 p = find_or_create_page(mapping, index, GFP_NOFS);
4259 spin_lock(&mapping->private_lock);
4260 if (PagePrivate(p)) {
4262 * We could have already allocated an eb for this page
4263 * and attached one so lets see if we can get a ref on
4264 * the existing eb, and if we can we know it's good and
4265 * we can just return that one, else we know we can just
4266 * overwrite page->private.
4268 exists = (struct extent_buffer *)p->private;
4269 if (atomic_inc_not_zero(&exists->refs)) {
4270 spin_unlock(&mapping->private_lock);
4272 page_cache_release(p);
4273 mark_extent_buffer_accessed(exists);
4278 * Do this so attach doesn't complain and we need to
4279 * drop the ref the old guy had.
4281 ClearPagePrivate(p);
4282 WARN_ON(PageDirty(p));
4283 page_cache_release(p);
4285 attach_extent_buffer_page(eb, p);
4286 spin_unlock(&mapping->private_lock);
4287 WARN_ON(PageDirty(p));
4288 mark_page_accessed(p);
4290 if (!PageUptodate(p))
4294 * see below about how we avoid a nasty race with release page
4295 * and why we unlock later
4299 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4301 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
4305 spin_lock(&tree->buffer_lock);
4306 ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
4307 if (ret == -EEXIST) {
4308 exists = radix_tree_lookup(&tree->buffer,
4309 start >> PAGE_CACHE_SHIFT);
4310 if (!atomic_inc_not_zero(&exists->refs)) {
4311 spin_unlock(&tree->buffer_lock);
4312 radix_tree_preload_end();
4316 spin_unlock(&tree->buffer_lock);
4317 radix_tree_preload_end();
4318 mark_extent_buffer_accessed(exists);
4321 /* add one reference for the tree */
4322 check_buffer_tree_ref(eb);
4323 spin_unlock(&tree->buffer_lock);
4324 radix_tree_preload_end();
4327 * there is a race where release page may have
4328 * tried to find this extent buffer in the radix
4329 * but failed. It will tell the VM it is safe to
4330 * reclaim the, and it will clear the page private bit.
4331 * We must make sure to set the page private bit properly
4332 * after the extent buffer is in the radix tree so
4333 * it doesn't get lost
4335 SetPageChecked(eb->pages[0]);
4336 for (i = 1; i < num_pages; i++) {
4337 p = extent_buffer_page(eb, i);
4338 ClearPageChecked(p);
4341 unlock_page(eb->pages[0]);
4345 for (i = 0; i < num_pages; i++) {
4347 unlock_page(eb->pages[i]);
4350 WARN_ON(!atomic_dec_and_test(&eb->refs));
4351 btrfs_release_extent_buffer(eb);
4355 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
4356 u64 start, unsigned long len)
4358 struct extent_buffer *eb;
4361 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4362 if (eb && atomic_inc_not_zero(&eb->refs)) {
4364 mark_extent_buffer_accessed(eb);
4372 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
4374 struct extent_buffer *eb =
4375 container_of(head, struct extent_buffer, rcu_head);
4377 __free_extent_buffer(eb);
4380 /* Expects to have eb->eb_lock already held */
4381 static int release_extent_buffer(struct extent_buffer *eb, gfp_t mask)
4383 WARN_ON(atomic_read(&eb->refs) == 0);
4384 if (atomic_dec_and_test(&eb->refs)) {
4385 if (test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags)) {
4386 spin_unlock(&eb->refs_lock);
4388 struct extent_io_tree *tree = eb->tree;
4390 spin_unlock(&eb->refs_lock);
4392 spin_lock(&tree->buffer_lock);
4393 radix_tree_delete(&tree->buffer,
4394 eb->start >> PAGE_CACHE_SHIFT);
4395 spin_unlock(&tree->buffer_lock);
4398 /* Should be safe to release our pages at this point */
4399 btrfs_release_extent_buffer_page(eb, 0);
4400 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
4403 spin_unlock(&eb->refs_lock);
4408 void free_extent_buffer(struct extent_buffer *eb)
4413 spin_lock(&eb->refs_lock);
4414 if (atomic_read(&eb->refs) == 2 &&
4415 test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
4416 atomic_dec(&eb->refs);
4418 if (atomic_read(&eb->refs) == 2 &&
4419 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
4420 !extent_buffer_under_io(eb) &&
4421 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4422 atomic_dec(&eb->refs);
4425 * I know this is terrible, but it's temporary until we stop tracking
4426 * the uptodate bits and such for the extent buffers.
4428 release_extent_buffer(eb, GFP_ATOMIC);
4431 void free_extent_buffer_stale(struct extent_buffer *eb)
4436 spin_lock(&eb->refs_lock);
4437 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
4439 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
4440 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4441 atomic_dec(&eb->refs);
4442 release_extent_buffer(eb, GFP_NOFS);
4445 void clear_extent_buffer_dirty(struct extent_buffer *eb)
4448 unsigned long num_pages;
4451 num_pages = num_extent_pages(eb->start, eb->len);
4453 for (i = 0; i < num_pages; i++) {
4454 page = extent_buffer_page(eb, i);
4455 if (!PageDirty(page))
4459 WARN_ON(!PagePrivate(page));
4461 clear_page_dirty_for_io(page);
4462 spin_lock_irq(&page->mapping->tree_lock);
4463 if (!PageDirty(page)) {
4464 radix_tree_tag_clear(&page->mapping->page_tree,
4466 PAGECACHE_TAG_DIRTY);
4468 spin_unlock_irq(&page->mapping->tree_lock);
4469 ClearPageError(page);
4472 WARN_ON(atomic_read(&eb->refs) == 0);
4475 int set_extent_buffer_dirty(struct extent_buffer *eb)
4478 unsigned long num_pages;
4481 check_buffer_tree_ref(eb);
4483 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
4485 num_pages = num_extent_pages(eb->start, eb->len);
4486 WARN_ON(atomic_read(&eb->refs) == 0);
4487 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
4489 for (i = 0; i < num_pages; i++)
4490 set_page_dirty(extent_buffer_page(eb, i));
4494 static int range_straddles_pages(u64 start, u64 len)
4496 if (len < PAGE_CACHE_SIZE)
4498 if (start & (PAGE_CACHE_SIZE - 1))
4500 if ((start + len) & (PAGE_CACHE_SIZE - 1))
4505 int clear_extent_buffer_uptodate(struct extent_buffer *eb)
4509 unsigned long num_pages;
4511 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4512 num_pages = num_extent_pages(eb->start, eb->len);
4513 for (i = 0; i < num_pages; i++) {
4514 page = extent_buffer_page(eb, i);
4516 ClearPageUptodate(page);
4521 int set_extent_buffer_uptodate(struct extent_buffer *eb)
4525 unsigned long num_pages;
4527 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4528 num_pages = num_extent_pages(eb->start, eb->len);
4529 for (i = 0; i < num_pages; i++) {
4530 page = extent_buffer_page(eb, i);
4531 SetPageUptodate(page);
4536 int extent_range_uptodate(struct extent_io_tree *tree,
4541 int pg_uptodate = 1;
4543 unsigned long index;
4545 if (range_straddles_pages(start, end - start + 1)) {
4546 ret = test_range_bit(tree, start, end,
4547 EXTENT_UPTODATE, 1, NULL);
4551 while (start <= end) {
4552 index = start >> PAGE_CACHE_SHIFT;
4553 page = find_get_page(tree->mapping, index);
4556 uptodate = PageUptodate(page);
4557 page_cache_release(page);
4562 start += PAGE_CACHE_SIZE;
4567 int extent_buffer_uptodate(struct extent_buffer *eb)
4569 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4572 int read_extent_buffer_pages(struct extent_io_tree *tree,
4573 struct extent_buffer *eb, u64 start, int wait,
4574 get_extent_t *get_extent, int mirror_num)
4577 unsigned long start_i;
4581 int locked_pages = 0;
4582 int all_uptodate = 1;
4583 unsigned long num_pages;
4584 unsigned long num_reads = 0;
4585 struct bio *bio = NULL;
4586 unsigned long bio_flags = 0;
4588 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
4592 WARN_ON(start < eb->start);
4593 start_i = (start >> PAGE_CACHE_SHIFT) -
4594 (eb->start >> PAGE_CACHE_SHIFT);
4599 num_pages = num_extent_pages(eb->start, eb->len);
4600 for (i = start_i; i < num_pages; i++) {
4601 page = extent_buffer_page(eb, i);
4602 if (wait == WAIT_NONE) {
4603 if (!trylock_page(page))
4609 if (!PageUptodate(page)) {
4616 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4620 clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
4621 eb->read_mirror = 0;
4622 atomic_set(&eb->io_pages, num_reads);
4623 for (i = start_i; i < num_pages; i++) {
4624 page = extent_buffer_page(eb, i);
4625 if (!PageUptodate(page)) {
4626 ClearPageError(page);
4627 err = __extent_read_full_page(tree, page,
4629 mirror_num, &bio_flags);
4638 err = submit_one_bio(READ, bio, mirror_num, bio_flags);
4643 if (ret || wait != WAIT_COMPLETE)
4646 for (i = start_i; i < num_pages; i++) {
4647 page = extent_buffer_page(eb, i);
4648 wait_on_page_locked(page);
4649 if (!PageUptodate(page))
4657 while (locked_pages > 0) {
4658 page = extent_buffer_page(eb, i);
4666 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
4667 unsigned long start,
4674 char *dst = (char *)dstv;
4675 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4676 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4678 WARN_ON(start > eb->len);
4679 WARN_ON(start + len > eb->start + eb->len);
4681 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4684 page = extent_buffer_page(eb, i);
4686 cur = min(len, (PAGE_CACHE_SIZE - offset));
4687 kaddr = page_address(page);
4688 memcpy(dst, kaddr + offset, cur);
4697 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
4698 unsigned long min_len, char **map,
4699 unsigned long *map_start,
4700 unsigned long *map_len)
4702 size_t offset = start & (PAGE_CACHE_SIZE - 1);
4705 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4706 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4707 unsigned long end_i = (start_offset + start + min_len - 1) >>
4714 offset = start_offset;
4718 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
4721 if (start + min_len > eb->len) {
4722 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
4723 "wanted %lu %lu\n", (unsigned long long)eb->start,
4724 eb->len, start, min_len);
4728 p = extent_buffer_page(eb, i);
4729 kaddr = page_address(p);
4730 *map = kaddr + offset;
4731 *map_len = PAGE_CACHE_SIZE - offset;
4735 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
4736 unsigned long start,
4743 char *ptr = (char *)ptrv;
4744 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4745 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4748 WARN_ON(start > eb->len);
4749 WARN_ON(start + len > eb->start + eb->len);
4751 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4754 page = extent_buffer_page(eb, i);
4756 cur = min(len, (PAGE_CACHE_SIZE - offset));
4758 kaddr = page_address(page);
4759 ret = memcmp(ptr, kaddr + offset, cur);
4771 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
4772 unsigned long start, unsigned long len)
4778 char *src = (char *)srcv;
4779 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4780 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4782 WARN_ON(start > eb->len);
4783 WARN_ON(start + len > eb->start + eb->len);
4785 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4788 page = extent_buffer_page(eb, i);
4789 WARN_ON(!PageUptodate(page));
4791 cur = min(len, PAGE_CACHE_SIZE - offset);
4792 kaddr = page_address(page);
4793 memcpy(kaddr + offset, src, cur);
4802 void memset_extent_buffer(struct extent_buffer *eb, char c,
4803 unsigned long start, unsigned long len)
4809 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4810 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4812 WARN_ON(start > eb->len);
4813 WARN_ON(start + len > eb->start + eb->len);
4815 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4818 page = extent_buffer_page(eb, i);
4819 WARN_ON(!PageUptodate(page));
4821 cur = min(len, PAGE_CACHE_SIZE - offset);
4822 kaddr = page_address(page);
4823 memset(kaddr + offset, c, cur);
4831 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
4832 unsigned long dst_offset, unsigned long src_offset,
4835 u64 dst_len = dst->len;
4840 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4841 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4843 WARN_ON(src->len != dst_len);
4845 offset = (start_offset + dst_offset) &
4846 ((unsigned long)PAGE_CACHE_SIZE - 1);
4849 page = extent_buffer_page(dst, i);
4850 WARN_ON(!PageUptodate(page));
4852 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
4854 kaddr = page_address(page);
4855 read_extent_buffer(src, kaddr + offset, src_offset, cur);
4864 static void move_pages(struct page *dst_page, struct page *src_page,
4865 unsigned long dst_off, unsigned long src_off,
4868 char *dst_kaddr = page_address(dst_page);
4869 if (dst_page == src_page) {
4870 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
4872 char *src_kaddr = page_address(src_page);
4873 char *p = dst_kaddr + dst_off + len;
4874 char *s = src_kaddr + src_off + len;
4881 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
4883 unsigned long distance = (src > dst) ? src - dst : dst - src;
4884 return distance < len;
4887 static void copy_pages(struct page *dst_page, struct page *src_page,
4888 unsigned long dst_off, unsigned long src_off,
4891 char *dst_kaddr = page_address(dst_page);
4893 int must_memmove = 0;
4895 if (dst_page != src_page) {
4896 src_kaddr = page_address(src_page);
4898 src_kaddr = dst_kaddr;
4899 if (areas_overlap(src_off, dst_off, len))
4904 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
4906 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
4909 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
4910 unsigned long src_offset, unsigned long len)
4913 size_t dst_off_in_page;
4914 size_t src_off_in_page;
4915 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4916 unsigned long dst_i;
4917 unsigned long src_i;
4919 if (src_offset + len > dst->len) {
4920 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4921 "len %lu dst len %lu\n", src_offset, len, dst->len);
4924 if (dst_offset + len > dst->len) {
4925 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4926 "len %lu dst len %lu\n", dst_offset, len, dst->len);
4931 dst_off_in_page = (start_offset + dst_offset) &
4932 ((unsigned long)PAGE_CACHE_SIZE - 1);
4933 src_off_in_page = (start_offset + src_offset) &
4934 ((unsigned long)PAGE_CACHE_SIZE - 1);
4936 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4937 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
4939 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
4941 cur = min_t(unsigned long, cur,
4942 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
4944 copy_pages(extent_buffer_page(dst, dst_i),
4945 extent_buffer_page(dst, src_i),
4946 dst_off_in_page, src_off_in_page, cur);
4954 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
4955 unsigned long src_offset, unsigned long len)
4958 size_t dst_off_in_page;
4959 size_t src_off_in_page;
4960 unsigned long dst_end = dst_offset + len - 1;
4961 unsigned long src_end = src_offset + len - 1;
4962 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4963 unsigned long dst_i;
4964 unsigned long src_i;
4966 if (src_offset + len > dst->len) {
4967 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4968 "len %lu len %lu\n", src_offset, len, dst->len);
4971 if (dst_offset + len > dst->len) {
4972 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4973 "len %lu len %lu\n", dst_offset, len, dst->len);
4976 if (dst_offset < src_offset) {
4977 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
4981 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
4982 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
4984 dst_off_in_page = (start_offset + dst_end) &
4985 ((unsigned long)PAGE_CACHE_SIZE - 1);
4986 src_off_in_page = (start_offset + src_end) &
4987 ((unsigned long)PAGE_CACHE_SIZE - 1);
4989 cur = min_t(unsigned long, len, src_off_in_page + 1);
4990 cur = min(cur, dst_off_in_page + 1);
4991 move_pages(extent_buffer_page(dst, dst_i),
4992 extent_buffer_page(dst, src_i),
4993 dst_off_in_page - cur + 1,
4994 src_off_in_page - cur + 1, cur);
5002 int try_release_extent_buffer(struct page *page, gfp_t mask)
5004 struct extent_buffer *eb;
5007 * We need to make sure noboody is attaching this page to an eb right
5010 spin_lock(&page->mapping->private_lock);
5011 if (!PagePrivate(page)) {
5012 spin_unlock(&page->mapping->private_lock);
5016 eb = (struct extent_buffer *)page->private;
5020 * This is a little awful but should be ok, we need to make sure that
5021 * the eb doesn't disappear out from under us while we're looking at
5024 spin_lock(&eb->refs_lock);
5025 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5026 spin_unlock(&eb->refs_lock);
5027 spin_unlock(&page->mapping->private_lock);
5030 spin_unlock(&page->mapping->private_lock);
5032 if ((mask & GFP_NOFS) == GFP_NOFS)
5036 * If tree ref isn't set then we know the ref on this eb is a real ref,
5037 * so just return, this page will likely be freed soon anyway.
5039 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
5040 spin_unlock(&eb->refs_lock);
5044 return release_extent_buffer(eb, mask);