1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/spinlock.h>
8 #include <linux/blkdev.h>
9 #include <linux/swap.h>
10 #include <linux/writeback.h>
11 #include <linux/pagevec.h>
12 #include <linux/prefetch.h>
13 #include <linux/cleancache.h>
14 #include "extent_io.h"
15 #include "extent_map.h"
18 #include "btrfs_inode.h"
20 #include "check-integrity.h"
22 #include "rcu-string.h"
24 static struct kmem_cache *extent_state_cache;
25 static struct kmem_cache *extent_buffer_cache;
26 static struct bio_set *btrfs_bioset;
28 #ifdef CONFIG_BTRFS_DEBUG
29 static LIST_HEAD(buffers);
30 static LIST_HEAD(states);
32 static DEFINE_SPINLOCK(leak_lock);
35 void btrfs_leak_debug_add(struct list_head *new, struct list_head *head)
39 spin_lock_irqsave(&leak_lock, flags);
41 spin_unlock_irqrestore(&leak_lock, flags);
45 void btrfs_leak_debug_del(struct list_head *entry)
49 spin_lock_irqsave(&leak_lock, flags);
51 spin_unlock_irqrestore(&leak_lock, flags);
55 void btrfs_leak_debug_check(void)
57 struct extent_state *state;
58 struct extent_buffer *eb;
60 while (!list_empty(&states)) {
61 state = list_entry(states.next, struct extent_state, leak_list);
62 printk(KERN_ERR "btrfs state leak: start %llu end %llu "
63 "state %lu in tree %p refs %d\n",
64 (unsigned long long)state->start,
65 (unsigned long long)state->end,
66 state->state, state->tree, atomic_read(&state->refs));
67 list_del(&state->leak_list);
68 kmem_cache_free(extent_state_cache, state);
71 while (!list_empty(&buffers)) {
72 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
73 printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
74 "refs %d\n", (unsigned long long)eb->start,
75 eb->len, atomic_read(&eb->refs));
76 list_del(&eb->leak_list);
77 kmem_cache_free(extent_buffer_cache, eb);
81 #define btrfs_leak_debug_add(new, head) do {} while (0)
82 #define btrfs_leak_debug_del(entry) do {} while (0)
83 #define btrfs_leak_debug_check() do {} while (0)
86 #define BUFFER_LRU_MAX 64
91 struct rb_node rb_node;
94 struct extent_page_data {
96 struct extent_io_tree *tree;
97 get_extent_t *get_extent;
98 unsigned long bio_flags;
100 /* tells writepage not to lock the state bits for this range
101 * it still does the unlocking
103 unsigned int extent_locked:1;
105 /* tells the submit_bio code to use a WRITE_SYNC */
106 unsigned int sync_io:1;
109 static noinline void flush_write_bio(void *data);
110 static inline struct btrfs_fs_info *
111 tree_fs_info(struct extent_io_tree *tree)
113 return btrfs_sb(tree->mapping->host->i_sb);
116 int __init extent_io_init(void)
118 extent_state_cache = kmem_cache_create("btrfs_extent_state",
119 sizeof(struct extent_state), 0,
120 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
121 if (!extent_state_cache)
124 extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
125 sizeof(struct extent_buffer), 0,
126 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
127 if (!extent_buffer_cache)
128 goto free_state_cache;
130 btrfs_bioset = bioset_create(BIO_POOL_SIZE,
131 offsetof(struct btrfs_io_bio, bio));
133 goto free_buffer_cache;
137 kmem_cache_destroy(extent_buffer_cache);
138 extent_buffer_cache = NULL;
141 kmem_cache_destroy(extent_state_cache);
142 extent_state_cache = NULL;
146 void extent_io_exit(void)
148 btrfs_leak_debug_check();
151 * Make sure all delayed rcu free are flushed before we
155 if (extent_state_cache)
156 kmem_cache_destroy(extent_state_cache);
157 if (extent_buffer_cache)
158 kmem_cache_destroy(extent_buffer_cache);
160 bioset_free(btrfs_bioset);
163 void extent_io_tree_init(struct extent_io_tree *tree,
164 struct address_space *mapping)
166 tree->state = RB_ROOT;
167 INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
169 tree->dirty_bytes = 0;
170 spin_lock_init(&tree->lock);
171 spin_lock_init(&tree->buffer_lock);
172 tree->mapping = mapping;
175 static struct extent_state *alloc_extent_state(gfp_t mask)
177 struct extent_state *state;
179 state = kmem_cache_alloc(extent_state_cache, mask);
185 btrfs_leak_debug_add(&state->leak_list, &states);
186 atomic_set(&state->refs, 1);
187 init_waitqueue_head(&state->wq);
188 trace_alloc_extent_state(state, mask, _RET_IP_);
192 void free_extent_state(struct extent_state *state)
196 if (atomic_dec_and_test(&state->refs)) {
197 WARN_ON(state->tree);
198 btrfs_leak_debug_del(&state->leak_list);
199 trace_free_extent_state(state, _RET_IP_);
200 kmem_cache_free(extent_state_cache, state);
204 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
205 struct rb_node *node)
207 struct rb_node **p = &root->rb_node;
208 struct rb_node *parent = NULL;
209 struct tree_entry *entry;
213 entry = rb_entry(parent, struct tree_entry, rb_node);
215 if (offset < entry->start)
217 else if (offset > entry->end)
223 rb_link_node(node, parent, p);
224 rb_insert_color(node, root);
228 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
229 struct rb_node **prev_ret,
230 struct rb_node **next_ret)
232 struct rb_root *root = &tree->state;
233 struct rb_node *n = root->rb_node;
234 struct rb_node *prev = NULL;
235 struct rb_node *orig_prev = NULL;
236 struct tree_entry *entry;
237 struct tree_entry *prev_entry = NULL;
240 entry = rb_entry(n, struct tree_entry, rb_node);
244 if (offset < entry->start)
246 else if (offset > entry->end)
254 while (prev && offset > prev_entry->end) {
255 prev = rb_next(prev);
256 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
263 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
264 while (prev && offset < prev_entry->start) {
265 prev = rb_prev(prev);
266 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
273 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
276 struct rb_node *prev = NULL;
279 ret = __etree_search(tree, offset, &prev, NULL);
285 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
286 struct extent_state *other)
288 if (tree->ops && tree->ops->merge_extent_hook)
289 tree->ops->merge_extent_hook(tree->mapping->host, new,
294 * utility function to look for merge candidates inside a given range.
295 * Any extents with matching state are merged together into a single
296 * extent in the tree. Extents with EXTENT_IO in their state field
297 * are not merged because the end_io handlers need to be able to do
298 * operations on them without sleeping (or doing allocations/splits).
300 * This should be called with the tree lock held.
302 static void merge_state(struct extent_io_tree *tree,
303 struct extent_state *state)
305 struct extent_state *other;
306 struct rb_node *other_node;
308 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
311 other_node = rb_prev(&state->rb_node);
313 other = rb_entry(other_node, struct extent_state, rb_node);
314 if (other->end == state->start - 1 &&
315 other->state == state->state) {
316 merge_cb(tree, state, other);
317 state->start = other->start;
319 rb_erase(&other->rb_node, &tree->state);
320 free_extent_state(other);
323 other_node = rb_next(&state->rb_node);
325 other = rb_entry(other_node, struct extent_state, rb_node);
326 if (other->start == state->end + 1 &&
327 other->state == state->state) {
328 merge_cb(tree, state, other);
329 state->end = other->end;
331 rb_erase(&other->rb_node, &tree->state);
332 free_extent_state(other);
337 static void set_state_cb(struct extent_io_tree *tree,
338 struct extent_state *state, unsigned long *bits)
340 if (tree->ops && tree->ops->set_bit_hook)
341 tree->ops->set_bit_hook(tree->mapping->host, state, bits);
344 static void clear_state_cb(struct extent_io_tree *tree,
345 struct extent_state *state, unsigned long *bits)
347 if (tree->ops && tree->ops->clear_bit_hook)
348 tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
351 static void set_state_bits(struct extent_io_tree *tree,
352 struct extent_state *state, unsigned long *bits);
355 * insert an extent_state struct into the tree. 'bits' are set on the
356 * struct before it is inserted.
358 * This may return -EEXIST if the extent is already there, in which case the
359 * state struct is freed.
361 * The tree lock is not taken internally. This is a utility function and
362 * probably isn't what you want to call (see set/clear_extent_bit).
364 static int insert_state(struct extent_io_tree *tree,
365 struct extent_state *state, u64 start, u64 end,
368 struct rb_node *node;
371 WARN(1, KERN_ERR "btrfs end < start %llu %llu\n",
372 (unsigned long long)end,
373 (unsigned long long)start);
374 state->start = start;
377 set_state_bits(tree, state, bits);
379 node = tree_insert(&tree->state, end, &state->rb_node);
381 struct extent_state *found;
382 found = rb_entry(node, struct extent_state, rb_node);
383 printk(KERN_ERR "btrfs found node %llu %llu on insert of "
384 "%llu %llu\n", (unsigned long long)found->start,
385 (unsigned long long)found->end,
386 (unsigned long long)start, (unsigned long long)end);
390 merge_state(tree, state);
394 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
397 if (tree->ops && tree->ops->split_extent_hook)
398 tree->ops->split_extent_hook(tree->mapping->host, orig, split);
402 * split a given extent state struct in two, inserting the preallocated
403 * struct 'prealloc' as the newly created second half. 'split' indicates an
404 * offset inside 'orig' where it should be split.
407 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
408 * are two extent state structs in the tree:
409 * prealloc: [orig->start, split - 1]
410 * orig: [ split, orig->end ]
412 * The tree locks are not taken by this function. They need to be held
415 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
416 struct extent_state *prealloc, u64 split)
418 struct rb_node *node;
420 split_cb(tree, orig, split);
422 prealloc->start = orig->start;
423 prealloc->end = split - 1;
424 prealloc->state = orig->state;
427 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
429 free_extent_state(prealloc);
432 prealloc->tree = tree;
436 static struct extent_state *next_state(struct extent_state *state)
438 struct rb_node *next = rb_next(&state->rb_node);
440 return rb_entry(next, struct extent_state, rb_node);
446 * utility function to clear some bits in an extent state struct.
447 * it will optionally wake up any one waiting on this state (wake == 1).
449 * If no bits are set on the state struct after clearing things, the
450 * struct is freed and removed from the tree
452 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
453 struct extent_state *state,
454 unsigned long *bits, int wake)
456 struct extent_state *next;
457 unsigned long bits_to_clear = *bits & ~EXTENT_CTLBITS;
459 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
460 u64 range = state->end - state->start + 1;
461 WARN_ON(range > tree->dirty_bytes);
462 tree->dirty_bytes -= range;
464 clear_state_cb(tree, state, bits);
465 state->state &= ~bits_to_clear;
468 if (state->state == 0) {
469 next = next_state(state);
471 rb_erase(&state->rb_node, &tree->state);
473 free_extent_state(state);
478 merge_state(tree, state);
479 next = next_state(state);
484 static struct extent_state *
485 alloc_extent_state_atomic(struct extent_state *prealloc)
488 prealloc = alloc_extent_state(GFP_ATOMIC);
493 static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
495 btrfs_panic(tree_fs_info(tree), err, "Locking error: "
496 "Extent tree was modified by another "
497 "thread while locked.");
501 * clear some bits on a range in the tree. This may require splitting
502 * or inserting elements in the tree, so the gfp mask is used to
503 * indicate which allocations or sleeping are allowed.
505 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
506 * the given range from the tree regardless of state (ie for truncate).
508 * the range [start, end] is inclusive.
510 * This takes the tree lock, and returns 0 on success and < 0 on error.
512 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
513 unsigned long bits, int wake, int delete,
514 struct extent_state **cached_state,
517 struct extent_state *state;
518 struct extent_state *cached;
519 struct extent_state *prealloc = NULL;
520 struct rb_node *node;
526 bits |= ~EXTENT_CTLBITS;
527 bits |= EXTENT_FIRST_DELALLOC;
529 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
532 if (!prealloc && (mask & __GFP_WAIT)) {
533 prealloc = alloc_extent_state(mask);
538 spin_lock(&tree->lock);
540 cached = *cached_state;
543 *cached_state = NULL;
547 if (cached && cached->tree && cached->start <= start &&
548 cached->end > start) {
550 atomic_dec(&cached->refs);
555 free_extent_state(cached);
558 * this search will find the extents that end after
561 node = tree_search(tree, start);
564 state = rb_entry(node, struct extent_state, rb_node);
566 if (state->start > end)
568 WARN_ON(state->end < start);
569 last_end = state->end;
571 /* the state doesn't have the wanted bits, go ahead */
572 if (!(state->state & bits)) {
573 state = next_state(state);
578 * | ---- desired range ---- |
580 * | ------------- state -------------- |
582 * We need to split the extent we found, and may flip
583 * bits on second half.
585 * If the extent we found extends past our range, we
586 * just split and search again. It'll get split again
587 * the next time though.
589 * If the extent we found is inside our range, we clear
590 * the desired bit on it.
593 if (state->start < start) {
594 prealloc = alloc_extent_state_atomic(prealloc);
596 err = split_state(tree, state, prealloc, start);
598 extent_io_tree_panic(tree, err);
603 if (state->end <= end) {
604 state = clear_state_bit(tree, state, &bits, wake);
610 * | ---- desired range ---- |
612 * We need to split the extent, and clear the bit
615 if (state->start <= end && state->end > end) {
616 prealloc = alloc_extent_state_atomic(prealloc);
618 err = split_state(tree, state, prealloc, end + 1);
620 extent_io_tree_panic(tree, err);
625 clear_state_bit(tree, prealloc, &bits, wake);
631 state = clear_state_bit(tree, state, &bits, wake);
633 if (last_end == (u64)-1)
635 start = last_end + 1;
636 if (start <= end && state && !need_resched())
641 spin_unlock(&tree->lock);
643 free_extent_state(prealloc);
650 spin_unlock(&tree->lock);
651 if (mask & __GFP_WAIT)
656 static void wait_on_state(struct extent_io_tree *tree,
657 struct extent_state *state)
658 __releases(tree->lock)
659 __acquires(tree->lock)
662 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
663 spin_unlock(&tree->lock);
665 spin_lock(&tree->lock);
666 finish_wait(&state->wq, &wait);
670 * waits for one or more bits to clear on a range in the state tree.
671 * The range [start, end] is inclusive.
672 * The tree lock is taken by this function
674 static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
677 struct extent_state *state;
678 struct rb_node *node;
680 spin_lock(&tree->lock);
684 * this search will find all the extents that end after
687 node = tree_search(tree, start);
691 state = rb_entry(node, struct extent_state, rb_node);
693 if (state->start > end)
696 if (state->state & bits) {
697 start = state->start;
698 atomic_inc(&state->refs);
699 wait_on_state(tree, state);
700 free_extent_state(state);
703 start = state->end + 1;
708 cond_resched_lock(&tree->lock);
711 spin_unlock(&tree->lock);
714 static void set_state_bits(struct extent_io_tree *tree,
715 struct extent_state *state,
718 unsigned long bits_to_set = *bits & ~EXTENT_CTLBITS;
720 set_state_cb(tree, state, bits);
721 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
722 u64 range = state->end - state->start + 1;
723 tree->dirty_bytes += range;
725 state->state |= bits_to_set;
728 static void cache_state(struct extent_state *state,
729 struct extent_state **cached_ptr)
731 if (cached_ptr && !(*cached_ptr)) {
732 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
734 atomic_inc(&state->refs);
739 static void uncache_state(struct extent_state **cached_ptr)
741 if (cached_ptr && (*cached_ptr)) {
742 struct extent_state *state = *cached_ptr;
744 free_extent_state(state);
749 * set some bits on a range in the tree. This may require allocations or
750 * sleeping, so the gfp mask is used to indicate what is allowed.
752 * If any of the exclusive bits are set, this will fail with -EEXIST if some
753 * part of the range already has the desired bits set. The start of the
754 * existing range is returned in failed_start in this case.
756 * [start, end] is inclusive This takes the tree lock.
759 static int __must_check
760 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
761 unsigned long bits, unsigned long exclusive_bits,
762 u64 *failed_start, struct extent_state **cached_state,
765 struct extent_state *state;
766 struct extent_state *prealloc = NULL;
767 struct rb_node *node;
772 bits |= EXTENT_FIRST_DELALLOC;
774 if (!prealloc && (mask & __GFP_WAIT)) {
775 prealloc = alloc_extent_state(mask);
779 spin_lock(&tree->lock);
780 if (cached_state && *cached_state) {
781 state = *cached_state;
782 if (state->start <= start && state->end > start &&
784 node = &state->rb_node;
789 * this search will find all the extents that end after
792 node = tree_search(tree, start);
794 prealloc = alloc_extent_state_atomic(prealloc);
796 err = insert_state(tree, prealloc, start, end, &bits);
798 extent_io_tree_panic(tree, err);
803 state = rb_entry(node, struct extent_state, rb_node);
805 last_start = state->start;
806 last_end = state->end;
809 * | ---- desired range ---- |
812 * Just lock what we found and keep going
814 if (state->start == start && state->end <= end) {
815 if (state->state & exclusive_bits) {
816 *failed_start = state->start;
821 set_state_bits(tree, state, &bits);
822 cache_state(state, cached_state);
823 merge_state(tree, state);
824 if (last_end == (u64)-1)
826 start = last_end + 1;
827 state = next_state(state);
828 if (start < end && state && state->start == start &&
835 * | ---- desired range ---- |
838 * | ------------- state -------------- |
840 * We need to split the extent we found, and may flip bits on
843 * If the extent we found extends past our
844 * range, we just split and search again. It'll get split
845 * again the next time though.
847 * If the extent we found is inside our range, we set the
850 if (state->start < start) {
851 if (state->state & exclusive_bits) {
852 *failed_start = start;
857 prealloc = alloc_extent_state_atomic(prealloc);
859 err = split_state(tree, state, prealloc, start);
861 extent_io_tree_panic(tree, err);
866 if (state->end <= end) {
867 set_state_bits(tree, state, &bits);
868 cache_state(state, cached_state);
869 merge_state(tree, state);
870 if (last_end == (u64)-1)
872 start = last_end + 1;
873 state = next_state(state);
874 if (start < end && state && state->start == start &&
881 * | ---- desired range ---- |
882 * | state | or | state |
884 * There's a hole, we need to insert something in it and
885 * ignore the extent we found.
887 if (state->start > start) {
889 if (end < last_start)
892 this_end = last_start - 1;
894 prealloc = alloc_extent_state_atomic(prealloc);
898 * Avoid to free 'prealloc' if it can be merged with
901 err = insert_state(tree, prealloc, start, this_end,
904 extent_io_tree_panic(tree, err);
906 cache_state(prealloc, cached_state);
908 start = this_end + 1;
912 * | ---- desired range ---- |
914 * We need to split the extent, and set the bit
917 if (state->start <= end && state->end > end) {
918 if (state->state & exclusive_bits) {
919 *failed_start = start;
924 prealloc = alloc_extent_state_atomic(prealloc);
926 err = split_state(tree, state, prealloc, end + 1);
928 extent_io_tree_panic(tree, err);
930 set_state_bits(tree, prealloc, &bits);
931 cache_state(prealloc, cached_state);
932 merge_state(tree, prealloc);
940 spin_unlock(&tree->lock);
942 free_extent_state(prealloc);
949 spin_unlock(&tree->lock);
950 if (mask & __GFP_WAIT)
955 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
956 unsigned long bits, u64 * failed_start,
957 struct extent_state **cached_state, gfp_t mask)
959 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
965 * convert_extent_bit - convert all bits in a given range from one bit to
967 * @tree: the io tree to search
968 * @start: the start offset in bytes
969 * @end: the end offset in bytes (inclusive)
970 * @bits: the bits to set in this range
971 * @clear_bits: the bits to clear in this range
972 * @cached_state: state that we're going to cache
973 * @mask: the allocation mask
975 * This will go through and set bits for the given range. If any states exist
976 * already in this range they are set with the given bit and cleared of the
977 * clear_bits. This is only meant to be used by things that are mergeable, ie
978 * converting from say DELALLOC to DIRTY. This is not meant to be used with
979 * boundary bits like LOCK.
981 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
982 unsigned long bits, unsigned long clear_bits,
983 struct extent_state **cached_state, gfp_t mask)
985 struct extent_state *state;
986 struct extent_state *prealloc = NULL;
987 struct rb_node *node;
993 if (!prealloc && (mask & __GFP_WAIT)) {
994 prealloc = alloc_extent_state(mask);
999 spin_lock(&tree->lock);
1000 if (cached_state && *cached_state) {
1001 state = *cached_state;
1002 if (state->start <= start && state->end > start &&
1004 node = &state->rb_node;
1010 * this search will find all the extents that end after
1013 node = tree_search(tree, start);
1015 prealloc = alloc_extent_state_atomic(prealloc);
1020 err = insert_state(tree, prealloc, start, end, &bits);
1023 extent_io_tree_panic(tree, err);
1026 state = rb_entry(node, struct extent_state, rb_node);
1028 last_start = state->start;
1029 last_end = state->end;
1032 * | ---- desired range ---- |
1035 * Just lock what we found and keep going
1037 if (state->start == start && state->end <= end) {
1038 set_state_bits(tree, state, &bits);
1039 cache_state(state, cached_state);
1040 state = clear_state_bit(tree, state, &clear_bits, 0);
1041 if (last_end == (u64)-1)
1043 start = last_end + 1;
1044 if (start < end && state && state->start == start &&
1051 * | ---- desired range ---- |
1054 * | ------------- state -------------- |
1056 * We need to split the extent we found, and may flip bits on
1059 * If the extent we found extends past our
1060 * range, we just split and search again. It'll get split
1061 * again the next time though.
1063 * If the extent we found is inside our range, we set the
1064 * desired bit on it.
1066 if (state->start < start) {
1067 prealloc = alloc_extent_state_atomic(prealloc);
1072 err = split_state(tree, state, prealloc, start);
1074 extent_io_tree_panic(tree, err);
1078 if (state->end <= end) {
1079 set_state_bits(tree, state, &bits);
1080 cache_state(state, cached_state);
1081 state = clear_state_bit(tree, state, &clear_bits, 0);
1082 if (last_end == (u64)-1)
1084 start = last_end + 1;
1085 if (start < end && state && state->start == start &&
1092 * | ---- desired range ---- |
1093 * | state | or | state |
1095 * There's a hole, we need to insert something in it and
1096 * ignore the extent we found.
1098 if (state->start > start) {
1100 if (end < last_start)
1103 this_end = last_start - 1;
1105 prealloc = alloc_extent_state_atomic(prealloc);
1112 * Avoid to free 'prealloc' if it can be merged with
1115 err = insert_state(tree, prealloc, start, this_end,
1118 extent_io_tree_panic(tree, err);
1119 cache_state(prealloc, cached_state);
1121 start = this_end + 1;
1125 * | ---- desired range ---- |
1127 * We need to split the extent, and set the bit
1130 if (state->start <= end && state->end > end) {
1131 prealloc = alloc_extent_state_atomic(prealloc);
1137 err = split_state(tree, state, prealloc, end + 1);
1139 extent_io_tree_panic(tree, err);
1141 set_state_bits(tree, prealloc, &bits);
1142 cache_state(prealloc, cached_state);
1143 clear_state_bit(tree, prealloc, &clear_bits, 0);
1151 spin_unlock(&tree->lock);
1153 free_extent_state(prealloc);
1160 spin_unlock(&tree->lock);
1161 if (mask & __GFP_WAIT)
1166 /* wrappers around set/clear extent bit */
1167 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1170 return set_extent_bit(tree, start, end, EXTENT_DIRTY, NULL,
1174 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1175 unsigned long bits, gfp_t mask)
1177 return set_extent_bit(tree, start, end, bits, NULL,
1181 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1182 unsigned long bits, gfp_t mask)
1184 return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
1187 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
1188 struct extent_state **cached_state, gfp_t mask)
1190 return set_extent_bit(tree, start, end,
1191 EXTENT_DELALLOC | EXTENT_UPTODATE,
1192 NULL, cached_state, mask);
1195 int set_extent_defrag(struct extent_io_tree *tree, u64 start, u64 end,
1196 struct extent_state **cached_state, gfp_t mask)
1198 return set_extent_bit(tree, start, end,
1199 EXTENT_DELALLOC | EXTENT_UPTODATE | EXTENT_DEFRAG,
1200 NULL, cached_state, mask);
1203 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1206 return clear_extent_bit(tree, start, end,
1207 EXTENT_DIRTY | EXTENT_DELALLOC |
1208 EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
1211 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
1214 return set_extent_bit(tree, start, end, EXTENT_NEW, NULL,
1218 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
1219 struct extent_state **cached_state, gfp_t mask)
1221 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, NULL,
1222 cached_state, mask);
1225 int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
1226 struct extent_state **cached_state, gfp_t mask)
1228 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
1229 cached_state, mask);
1233 * either insert or lock state struct between start and end use mask to tell
1234 * us if waiting is desired.
1236 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1237 unsigned long bits, struct extent_state **cached_state)
1242 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
1243 EXTENT_LOCKED, &failed_start,
1244 cached_state, GFP_NOFS);
1245 if (err == -EEXIST) {
1246 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1247 start = failed_start;
1250 WARN_ON(start > end);
1255 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1257 return lock_extent_bits(tree, start, end, 0, NULL);
1260 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1265 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1266 &failed_start, NULL, GFP_NOFS);
1267 if (err == -EEXIST) {
1268 if (failed_start > start)
1269 clear_extent_bit(tree, start, failed_start - 1,
1270 EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS);
1276 int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
1277 struct extent_state **cached, gfp_t mask)
1279 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
1283 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1285 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
1289 int extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
1291 unsigned long index = start >> PAGE_CACHE_SHIFT;
1292 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1295 while (index <= end_index) {
1296 page = find_get_page(inode->i_mapping, index);
1297 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1298 clear_page_dirty_for_io(page);
1299 page_cache_release(page);
1305 int extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
1307 unsigned long index = start >> PAGE_CACHE_SHIFT;
1308 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1311 while (index <= end_index) {
1312 page = find_get_page(inode->i_mapping, index);
1313 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1314 account_page_redirty(page);
1315 __set_page_dirty_nobuffers(page);
1316 page_cache_release(page);
1323 * helper function to set both pages and extents in the tree writeback
1325 static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1327 unsigned long index = start >> PAGE_CACHE_SHIFT;
1328 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1331 while (index <= end_index) {
1332 page = find_get_page(tree->mapping, index);
1333 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1334 set_page_writeback(page);
1335 page_cache_release(page);
1341 /* find the first state struct with 'bits' set after 'start', and
1342 * return it. tree->lock must be held. NULL will returned if
1343 * nothing was found after 'start'
1345 static struct extent_state *
1346 find_first_extent_bit_state(struct extent_io_tree *tree,
1347 u64 start, unsigned long bits)
1349 struct rb_node *node;
1350 struct extent_state *state;
1353 * this search will find all the extents that end after
1356 node = tree_search(tree, start);
1361 state = rb_entry(node, struct extent_state, rb_node);
1362 if (state->end >= start && (state->state & bits))
1365 node = rb_next(node);
1374 * find the first offset in the io tree with 'bits' set. zero is
1375 * returned if we find something, and *start_ret and *end_ret are
1376 * set to reflect the state struct that was found.
1378 * If nothing was found, 1 is returned. If found something, return 0.
1380 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1381 u64 *start_ret, u64 *end_ret, unsigned long bits,
1382 struct extent_state **cached_state)
1384 struct extent_state *state;
1388 spin_lock(&tree->lock);
1389 if (cached_state && *cached_state) {
1390 state = *cached_state;
1391 if (state->end == start - 1 && state->tree) {
1392 n = rb_next(&state->rb_node);
1394 state = rb_entry(n, struct extent_state,
1396 if (state->state & bits)
1400 free_extent_state(*cached_state);
1401 *cached_state = NULL;
1404 free_extent_state(*cached_state);
1405 *cached_state = NULL;
1408 state = find_first_extent_bit_state(tree, start, bits);
1411 cache_state(state, cached_state);
1412 *start_ret = state->start;
1413 *end_ret = state->end;
1417 spin_unlock(&tree->lock);
1422 * find a contiguous range of bytes in the file marked as delalloc, not
1423 * more than 'max_bytes'. start and end are used to return the range,
1425 * 1 is returned if we find something, 0 if nothing was in the tree
1427 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1428 u64 *start, u64 *end, u64 max_bytes,
1429 struct extent_state **cached_state)
1431 struct rb_node *node;
1432 struct extent_state *state;
1433 u64 cur_start = *start;
1435 u64 total_bytes = 0;
1437 spin_lock(&tree->lock);
1440 * this search will find all the extents that end after
1443 node = tree_search(tree, cur_start);
1451 state = rb_entry(node, struct extent_state, rb_node);
1452 if (found && (state->start != cur_start ||
1453 (state->state & EXTENT_BOUNDARY))) {
1456 if (!(state->state & EXTENT_DELALLOC)) {
1462 *start = state->start;
1463 *cached_state = state;
1464 atomic_inc(&state->refs);
1468 cur_start = state->end + 1;
1469 node = rb_next(node);
1472 total_bytes += state->end - state->start + 1;
1473 if (total_bytes >= max_bytes)
1477 spin_unlock(&tree->lock);
1481 static noinline void __unlock_for_delalloc(struct inode *inode,
1482 struct page *locked_page,
1486 struct page *pages[16];
1487 unsigned long index = start >> PAGE_CACHE_SHIFT;
1488 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1489 unsigned long nr_pages = end_index - index + 1;
1492 if (index == locked_page->index && end_index == index)
1495 while (nr_pages > 0) {
1496 ret = find_get_pages_contig(inode->i_mapping, index,
1497 min_t(unsigned long, nr_pages,
1498 ARRAY_SIZE(pages)), pages);
1499 for (i = 0; i < ret; i++) {
1500 if (pages[i] != locked_page)
1501 unlock_page(pages[i]);
1502 page_cache_release(pages[i]);
1510 static noinline int lock_delalloc_pages(struct inode *inode,
1511 struct page *locked_page,
1515 unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
1516 unsigned long start_index = index;
1517 unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
1518 unsigned long pages_locked = 0;
1519 struct page *pages[16];
1520 unsigned long nrpages;
1524 /* the caller is responsible for locking the start index */
1525 if (index == locked_page->index && index == end_index)
1528 /* skip the page at the start index */
1529 nrpages = end_index - index + 1;
1530 while (nrpages > 0) {
1531 ret = find_get_pages_contig(inode->i_mapping, index,
1532 min_t(unsigned long,
1533 nrpages, ARRAY_SIZE(pages)), pages);
1538 /* now we have an array of pages, lock them all */
1539 for (i = 0; i < ret; i++) {
1541 * the caller is taking responsibility for
1544 if (pages[i] != locked_page) {
1545 lock_page(pages[i]);
1546 if (!PageDirty(pages[i]) ||
1547 pages[i]->mapping != inode->i_mapping) {
1549 unlock_page(pages[i]);
1550 page_cache_release(pages[i]);
1554 page_cache_release(pages[i]);
1563 if (ret && pages_locked) {
1564 __unlock_for_delalloc(inode, locked_page,
1566 ((u64)(start_index + pages_locked - 1)) <<
1573 * find a contiguous range of bytes in the file marked as delalloc, not
1574 * more than 'max_bytes'. start and end are used to return the range,
1576 * 1 is returned if we find something, 0 if nothing was in the tree
1578 static noinline u64 find_lock_delalloc_range(struct inode *inode,
1579 struct extent_io_tree *tree,
1580 struct page *locked_page,
1581 u64 *start, u64 *end,
1587 struct extent_state *cached_state = NULL;
1592 /* step one, find a bunch of delalloc bytes starting at start */
1593 delalloc_start = *start;
1595 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1596 max_bytes, &cached_state);
1597 if (!found || delalloc_end <= *start) {
1598 *start = delalloc_start;
1599 *end = delalloc_end;
1600 free_extent_state(cached_state);
1605 * start comes from the offset of locked_page. We have to lock
1606 * pages in order, so we can't process delalloc bytes before
1609 if (delalloc_start < *start)
1610 delalloc_start = *start;
1613 * make sure to limit the number of pages we try to lock down
1616 if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1617 delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
1619 /* step two, lock all the pages after the page that has start */
1620 ret = lock_delalloc_pages(inode, locked_page,
1621 delalloc_start, delalloc_end);
1622 if (ret == -EAGAIN) {
1623 /* some of the pages are gone, lets avoid looping by
1624 * shortening the size of the delalloc range we're searching
1626 free_extent_state(cached_state);
1627 cached_state = NULL;
1629 unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
1630 max_bytes = PAGE_CACHE_SIZE - offset;
1638 BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
1640 /* step three, lock the state bits for the whole range */
1641 lock_extent_bits(tree, delalloc_start, delalloc_end, 0, &cached_state);
1643 /* then test to make sure it is all still delalloc */
1644 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1645 EXTENT_DELALLOC, 1, cached_state);
1647 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1648 &cached_state, GFP_NOFS);
1649 __unlock_for_delalloc(inode, locked_page,
1650 delalloc_start, delalloc_end);
1654 free_extent_state(cached_state);
1655 *start = delalloc_start;
1656 *end = delalloc_end;
1661 int extent_clear_unlock_delalloc(struct inode *inode,
1662 struct extent_io_tree *tree,
1663 u64 start, u64 end, struct page *locked_page,
1667 struct page *pages[16];
1668 unsigned long index = start >> PAGE_CACHE_SHIFT;
1669 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1670 unsigned long nr_pages = end_index - index + 1;
1672 unsigned long clear_bits = 0;
1674 if (op & EXTENT_CLEAR_UNLOCK)
1675 clear_bits |= EXTENT_LOCKED;
1676 if (op & EXTENT_CLEAR_DIRTY)
1677 clear_bits |= EXTENT_DIRTY;
1679 if (op & EXTENT_CLEAR_DELALLOC)
1680 clear_bits |= EXTENT_DELALLOC;
1682 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1683 if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
1684 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
1685 EXTENT_SET_PRIVATE2)))
1688 while (nr_pages > 0) {
1689 ret = find_get_pages_contig(inode->i_mapping, index,
1690 min_t(unsigned long,
1691 nr_pages, ARRAY_SIZE(pages)), pages);
1692 for (i = 0; i < ret; i++) {
1694 if (op & EXTENT_SET_PRIVATE2)
1695 SetPagePrivate2(pages[i]);
1697 if (pages[i] == locked_page) {
1698 page_cache_release(pages[i]);
1701 if (op & EXTENT_CLEAR_DIRTY)
1702 clear_page_dirty_for_io(pages[i]);
1703 if (op & EXTENT_SET_WRITEBACK)
1704 set_page_writeback(pages[i]);
1705 if (op & EXTENT_END_WRITEBACK)
1706 end_page_writeback(pages[i]);
1707 if (op & EXTENT_CLEAR_UNLOCK_PAGE)
1708 unlock_page(pages[i]);
1709 page_cache_release(pages[i]);
1719 * count the number of bytes in the tree that have a given bit(s)
1720 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1721 * cached. The total number found is returned.
1723 u64 count_range_bits(struct extent_io_tree *tree,
1724 u64 *start, u64 search_end, u64 max_bytes,
1725 unsigned long bits, int contig)
1727 struct rb_node *node;
1728 struct extent_state *state;
1729 u64 cur_start = *start;
1730 u64 total_bytes = 0;
1734 if (search_end <= cur_start) {
1739 spin_lock(&tree->lock);
1740 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1741 total_bytes = tree->dirty_bytes;
1745 * this search will find all the extents that end after
1748 node = tree_search(tree, cur_start);
1753 state = rb_entry(node, struct extent_state, rb_node);
1754 if (state->start > search_end)
1756 if (contig && found && state->start > last + 1)
1758 if (state->end >= cur_start && (state->state & bits) == bits) {
1759 total_bytes += min(search_end, state->end) + 1 -
1760 max(cur_start, state->start);
1761 if (total_bytes >= max_bytes)
1764 *start = max(cur_start, state->start);
1768 } else if (contig && found) {
1771 node = rb_next(node);
1776 spin_unlock(&tree->lock);
1781 * set the private field for a given byte offset in the tree. If there isn't
1782 * an extent_state there already, this does nothing.
1784 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1786 struct rb_node *node;
1787 struct extent_state *state;
1790 spin_lock(&tree->lock);
1792 * this search will find all the extents that end after
1795 node = tree_search(tree, start);
1800 state = rb_entry(node, struct extent_state, rb_node);
1801 if (state->start != start) {
1805 state->private = private;
1807 spin_unlock(&tree->lock);
1811 void extent_cache_csums_dio(struct extent_io_tree *tree, u64 start, u32 csums[],
1814 struct rb_node *node;
1815 struct extent_state *state;
1817 spin_lock(&tree->lock);
1819 * this search will find all the extents that end after
1822 node = tree_search(tree, start);
1825 state = rb_entry(node, struct extent_state, rb_node);
1826 BUG_ON(state->start != start);
1829 state->private = *csums++;
1831 state = next_state(state);
1833 spin_unlock(&tree->lock);
1836 static inline u64 __btrfs_get_bio_offset(struct bio *bio, int bio_index)
1838 struct bio_vec *bvec = bio->bi_io_vec + bio_index;
1840 return page_offset(bvec->bv_page) + bvec->bv_offset;
1843 void extent_cache_csums(struct extent_io_tree *tree, struct bio *bio, int bio_index,
1844 u32 csums[], int count)
1846 struct rb_node *node;
1847 struct extent_state *state = NULL;
1850 spin_lock(&tree->lock);
1852 start = __btrfs_get_bio_offset(bio, bio_index);
1853 if (state == NULL || state->start != start) {
1854 node = tree_search(tree, start);
1857 state = rb_entry(node, struct extent_state, rb_node);
1858 BUG_ON(state->start != start);
1860 state->private = *csums++;
1864 state = next_state(state);
1866 spin_unlock(&tree->lock);
1869 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1871 struct rb_node *node;
1872 struct extent_state *state;
1875 spin_lock(&tree->lock);
1877 * this search will find all the extents that end after
1880 node = tree_search(tree, start);
1885 state = rb_entry(node, struct extent_state, rb_node);
1886 if (state->start != start) {
1890 *private = state->private;
1892 spin_unlock(&tree->lock);
1897 * searches a range in the state tree for a given mask.
1898 * If 'filled' == 1, this returns 1 only if every extent in the tree
1899 * has the bits set. Otherwise, 1 is returned if any bit in the
1900 * range is found set.
1902 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1903 unsigned long bits, int filled, struct extent_state *cached)
1905 struct extent_state *state = NULL;
1906 struct rb_node *node;
1909 spin_lock(&tree->lock);
1910 if (cached && cached->tree && cached->start <= start &&
1911 cached->end > start)
1912 node = &cached->rb_node;
1914 node = tree_search(tree, start);
1915 while (node && start <= end) {
1916 state = rb_entry(node, struct extent_state, rb_node);
1918 if (filled && state->start > start) {
1923 if (state->start > end)
1926 if (state->state & bits) {
1930 } else if (filled) {
1935 if (state->end == (u64)-1)
1938 start = state->end + 1;
1941 node = rb_next(node);
1948 spin_unlock(&tree->lock);
1953 * helper function to set a given page up to date if all the
1954 * extents in the tree for that page are up to date
1956 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
1958 u64 start = page_offset(page);
1959 u64 end = start + PAGE_CACHE_SIZE - 1;
1960 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1961 SetPageUptodate(page);
1965 * When IO fails, either with EIO or csum verification fails, we
1966 * try other mirrors that might have a good copy of the data. This
1967 * io_failure_record is used to record state as we go through all the
1968 * mirrors. If another mirror has good data, the page is set up to date
1969 * and things continue. If a good mirror can't be found, the original
1970 * bio end_io callback is called to indicate things have failed.
1972 struct io_failure_record {
1977 unsigned long bio_flags;
1983 static int free_io_failure(struct inode *inode, struct io_failure_record *rec,
1988 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1990 set_state_private(failure_tree, rec->start, 0);
1991 ret = clear_extent_bits(failure_tree, rec->start,
1992 rec->start + rec->len - 1,
1993 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
1997 ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
1998 rec->start + rec->len - 1,
1999 EXTENT_DAMAGED, GFP_NOFS);
2007 static void repair_io_failure_callback(struct bio *bio, int err)
2009 complete(bio->bi_private);
2013 * this bypasses the standard btrfs submit functions deliberately, as
2014 * the standard behavior is to write all copies in a raid setup. here we only
2015 * want to write the one bad copy. so we do the mapping for ourselves and issue
2016 * submit_bio directly.
2017 * to avoid any synchronization issues, wait for the data after writing, which
2018 * actually prevents the read that triggered the error from finishing.
2019 * currently, there can be no more than two copies of every data bit. thus,
2020 * exactly one rewrite is required.
2022 int repair_io_failure(struct btrfs_fs_info *fs_info, u64 start,
2023 u64 length, u64 logical, struct page *page,
2027 struct btrfs_device *dev;
2028 DECLARE_COMPLETION_ONSTACK(compl);
2031 struct btrfs_bio *bbio = NULL;
2032 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
2035 BUG_ON(!mirror_num);
2037 /* we can't repair anything in raid56 yet */
2038 if (btrfs_is_parity_mirror(map_tree, logical, length, mirror_num))
2041 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2044 bio->bi_private = &compl;
2045 bio->bi_end_io = repair_io_failure_callback;
2047 map_length = length;
2049 ret = btrfs_map_block(fs_info, WRITE, logical,
2050 &map_length, &bbio, mirror_num);
2055 BUG_ON(mirror_num != bbio->mirror_num);
2056 sector = bbio->stripes[mirror_num-1].physical >> 9;
2057 bio->bi_sector = sector;
2058 dev = bbio->stripes[mirror_num-1].dev;
2060 if (!dev || !dev->bdev || !dev->writeable) {
2064 bio->bi_bdev = dev->bdev;
2065 bio_add_page(bio, page, length, start - page_offset(page));
2066 btrfsic_submit_bio(WRITE_SYNC, bio);
2067 wait_for_completion(&compl);
2069 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
2070 /* try to remap that extent elsewhere? */
2072 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2076 printk_ratelimited_in_rcu(KERN_INFO "btrfs read error corrected: ino %lu off %llu "
2077 "(dev %s sector %llu)\n", page->mapping->host->i_ino,
2078 start, rcu_str_deref(dev->name), sector);
2084 int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb,
2087 u64 start = eb->start;
2088 unsigned long i, num_pages = num_extent_pages(eb->start, eb->len);
2091 for (i = 0; i < num_pages; i++) {
2092 struct page *p = extent_buffer_page(eb, i);
2093 ret = repair_io_failure(root->fs_info, start, PAGE_CACHE_SIZE,
2094 start, p, mirror_num);
2097 start += PAGE_CACHE_SIZE;
2104 * each time an IO finishes, we do a fast check in the IO failure tree
2105 * to see if we need to process or clean up an io_failure_record
2107 static int clean_io_failure(u64 start, struct page *page)
2110 u64 private_failure;
2111 struct io_failure_record *failrec;
2112 struct btrfs_fs_info *fs_info;
2113 struct extent_state *state;
2117 struct inode *inode = page->mapping->host;
2120 ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
2121 (u64)-1, 1, EXTENT_DIRTY, 0);
2125 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree, start,
2130 failrec = (struct io_failure_record *)(unsigned long) private_failure;
2131 BUG_ON(!failrec->this_mirror);
2133 if (failrec->in_validation) {
2134 /* there was no real error, just free the record */
2135 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2141 spin_lock(&BTRFS_I(inode)->io_tree.lock);
2142 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
2145 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
2147 if (state && state->start == failrec->start) {
2148 fs_info = BTRFS_I(inode)->root->fs_info;
2149 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2151 if (num_copies > 1) {
2152 ret = repair_io_failure(fs_info, start, failrec->len,
2153 failrec->logical, page,
2154 failrec->failed_mirror);
2162 ret = free_io_failure(inode, failrec, did_repair);
2168 * this is a generic handler for readpage errors (default
2169 * readpage_io_failed_hook). if other copies exist, read those and write back
2170 * good data to the failed position. does not investigate in remapping the
2171 * failed extent elsewhere, hoping the device will be smart enough to do this as
2175 static int bio_readpage_error(struct bio *failed_bio, struct page *page,
2176 u64 start, u64 end, int failed_mirror,
2177 struct extent_state *state)
2179 struct io_failure_record *failrec = NULL;
2181 struct extent_map *em;
2182 struct inode *inode = page->mapping->host;
2183 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2184 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2185 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2192 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
2194 ret = get_state_private(failure_tree, start, &private);
2196 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2199 failrec->start = start;
2200 failrec->len = end - start + 1;
2201 failrec->this_mirror = 0;
2202 failrec->bio_flags = 0;
2203 failrec->in_validation = 0;
2205 read_lock(&em_tree->lock);
2206 em = lookup_extent_mapping(em_tree, start, failrec->len);
2208 read_unlock(&em_tree->lock);
2213 if (em->start > start || em->start + em->len < start) {
2214 free_extent_map(em);
2217 read_unlock(&em_tree->lock);
2223 logical = start - em->start;
2224 logical = em->block_start + logical;
2225 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2226 logical = em->block_start;
2227 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2228 extent_set_compress_type(&failrec->bio_flags,
2231 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2232 "len=%llu\n", logical, start, failrec->len);
2233 failrec->logical = logical;
2234 free_extent_map(em);
2236 /* set the bits in the private failure tree */
2237 ret = set_extent_bits(failure_tree, start, end,
2238 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
2240 ret = set_state_private(failure_tree, start,
2241 (u64)(unsigned long)failrec);
2242 /* set the bits in the inode's tree */
2244 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED,
2251 failrec = (struct io_failure_record *)(unsigned long)private;
2252 pr_debug("bio_readpage_error: (found) logical=%llu, "
2253 "start=%llu, len=%llu, validation=%d\n",
2254 failrec->logical, failrec->start, failrec->len,
2255 failrec->in_validation);
2257 * when data can be on disk more than twice, add to failrec here
2258 * (e.g. with a list for failed_mirror) to make
2259 * clean_io_failure() clean all those errors at once.
2262 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
2263 failrec->logical, failrec->len);
2264 if (num_copies == 1) {
2266 * we only have a single copy of the data, so don't bother with
2267 * all the retry and error correction code that follows. no
2268 * matter what the error is, it is very likely to persist.
2270 pr_debug("bio_readpage_error: cannot repair, num_copies == 1. "
2271 "state=%p, num_copies=%d, next_mirror %d, "
2272 "failed_mirror %d\n", state, num_copies,
2273 failrec->this_mirror, failed_mirror);
2274 free_io_failure(inode, failrec, 0);
2279 spin_lock(&tree->lock);
2280 state = find_first_extent_bit_state(tree, failrec->start,
2282 if (state && state->start != failrec->start)
2284 spin_unlock(&tree->lock);
2288 * there are two premises:
2289 * a) deliver good data to the caller
2290 * b) correct the bad sectors on disk
2292 if (failed_bio->bi_vcnt > 1) {
2294 * to fulfill b), we need to know the exact failing sectors, as
2295 * we don't want to rewrite any more than the failed ones. thus,
2296 * we need separate read requests for the failed bio
2298 * if the following BUG_ON triggers, our validation request got
2299 * merged. we need separate requests for our algorithm to work.
2301 BUG_ON(failrec->in_validation);
2302 failrec->in_validation = 1;
2303 failrec->this_mirror = failed_mirror;
2304 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
2307 * we're ready to fulfill a) and b) alongside. get a good copy
2308 * of the failed sector and if we succeed, we have setup
2309 * everything for repair_io_failure to do the rest for us.
2311 if (failrec->in_validation) {
2312 BUG_ON(failrec->this_mirror != failed_mirror);
2313 failrec->in_validation = 0;
2314 failrec->this_mirror = 0;
2316 failrec->failed_mirror = failed_mirror;
2317 failrec->this_mirror++;
2318 if (failrec->this_mirror == failed_mirror)
2319 failrec->this_mirror++;
2320 read_mode = READ_SYNC;
2323 if (!state || failrec->this_mirror > num_copies) {
2324 pr_debug("bio_readpage_error: (fail) state=%p, num_copies=%d, "
2325 "next_mirror %d, failed_mirror %d\n", state,
2326 num_copies, failrec->this_mirror, failed_mirror);
2327 free_io_failure(inode, failrec, 0);
2331 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2333 free_io_failure(inode, failrec, 0);
2336 bio->bi_private = state;
2337 bio->bi_end_io = failed_bio->bi_end_io;
2338 bio->bi_sector = failrec->logical >> 9;
2339 bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
2342 bio_add_page(bio, page, failrec->len, start - page_offset(page));
2344 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2345 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode,
2346 failrec->this_mirror, num_copies, failrec->in_validation);
2348 ret = tree->ops->submit_bio_hook(inode, read_mode, bio,
2349 failrec->this_mirror,
2350 failrec->bio_flags, 0);
2354 /* lots and lots of room for performance fixes in the end_bio funcs */
2356 int end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2358 int uptodate = (err == 0);
2359 struct extent_io_tree *tree;
2362 tree = &BTRFS_I(page->mapping->host)->io_tree;
2364 if (tree->ops && tree->ops->writepage_end_io_hook) {
2365 ret = tree->ops->writepage_end_io_hook(page, start,
2366 end, NULL, uptodate);
2372 ClearPageUptodate(page);
2374 ret = ret < 0 ? ret : -EIO;
2375 mapping_set_error(page->mapping, ret);
2381 * after a writepage IO is done, we need to:
2382 * clear the uptodate bits on error
2383 * clear the writeback bits in the extent tree for this IO
2384 * end_page_writeback if the page has no more pending IO
2386 * Scheduling is not allowed, so the extent state tree is expected
2387 * to have one and only one object corresponding to this IO.
2389 static void end_bio_extent_writepage(struct bio *bio, int err)
2391 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2392 struct extent_io_tree *tree;
2397 struct page *page = bvec->bv_page;
2398 tree = &BTRFS_I(page->mapping->host)->io_tree;
2400 /* We always issue full-page reads, but if some block
2401 * in a page fails to read, blk_update_request() will
2402 * advance bv_offset and adjust bv_len to compensate.
2403 * Print a warning for nonzero offsets, and an error
2404 * if they don't add up to a full page. */
2405 if (bvec->bv_offset || bvec->bv_len != PAGE_CACHE_SIZE)
2406 printk("%s page write in btrfs with offset %u and length %u\n",
2407 bvec->bv_offset + bvec->bv_len != PAGE_CACHE_SIZE
2408 ? KERN_ERR "partial" : KERN_INFO "incomplete",
2409 bvec->bv_offset, bvec->bv_len);
2411 start = page_offset(page);
2412 end = start + bvec->bv_offset + bvec->bv_len - 1;
2414 if (--bvec >= bio->bi_io_vec)
2415 prefetchw(&bvec->bv_page->flags);
2417 if (end_extent_writepage(page, err, start, end))
2420 end_page_writeback(page);
2421 } while (bvec >= bio->bi_io_vec);
2427 * after a readpage IO is done, we need to:
2428 * clear the uptodate bits on error
2429 * set the uptodate bits if things worked
2430 * set the page up to date if all extents in the tree are uptodate
2431 * clear the lock bit in the extent tree
2432 * unlock the page if there are no other extents locked for it
2434 * Scheduling is not allowed, so the extent state tree is expected
2435 * to have one and only one object corresponding to this IO.
2437 static void end_bio_extent_readpage(struct bio *bio, int err)
2439 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
2440 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
2441 struct bio_vec *bvec = bio->bi_io_vec;
2442 struct extent_io_tree *tree;
2452 struct page *page = bvec->bv_page;
2453 struct extent_state *cached = NULL;
2454 struct extent_state *state;
2455 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2457 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2458 "mirror=%lu\n", (u64)bio->bi_sector, err,
2459 io_bio->mirror_num);
2460 tree = &BTRFS_I(page->mapping->host)->io_tree;
2462 /* We always issue full-page reads, but if some block
2463 * in a page fails to read, blk_update_request() will
2464 * advance bv_offset and adjust bv_len to compensate.
2465 * Print a warning for nonzero offsets, and an error
2466 * if they don't add up to a full page. */
2467 if (bvec->bv_offset || bvec->bv_len != PAGE_CACHE_SIZE)
2468 printk("%s page read in btrfs with offset %u and length %u\n",
2469 bvec->bv_offset + bvec->bv_len != PAGE_CACHE_SIZE
2470 ? KERN_ERR "partial" : KERN_INFO "incomplete",
2471 bvec->bv_offset, bvec->bv_len);
2473 start = page_offset(page);
2474 end = start + bvec->bv_offset + bvec->bv_len - 1;
2476 if (++bvec <= bvec_end)
2477 prefetchw(&bvec->bv_page->flags);
2479 spin_lock(&tree->lock);
2480 state = find_first_extent_bit_state(tree, start, EXTENT_LOCKED);
2481 if (state && state->start == start) {
2483 * take a reference on the state, unlock will drop
2486 cache_state(state, &cached);
2488 spin_unlock(&tree->lock);
2490 mirror = io_bio->mirror_num;
2491 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
2492 ret = tree->ops->readpage_end_io_hook(page, start, end,
2497 clean_io_failure(start, page);
2500 if (!uptodate && tree->ops && tree->ops->readpage_io_failed_hook) {
2501 ret = tree->ops->readpage_io_failed_hook(page, mirror);
2503 test_bit(BIO_UPTODATE, &bio->bi_flags))
2505 } else if (!uptodate) {
2507 * The generic bio_readpage_error handles errors the
2508 * following way: If possible, new read requests are
2509 * created and submitted and will end up in
2510 * end_bio_extent_readpage as well (if we're lucky, not
2511 * in the !uptodate case). In that case it returns 0 and
2512 * we just go on with the next page in our bio. If it
2513 * can't handle the error it will return -EIO and we
2514 * remain responsible for that page.
2516 ret = bio_readpage_error(bio, page, start, end, mirror, NULL);
2519 test_bit(BIO_UPTODATE, &bio->bi_flags);
2522 uncache_state(&cached);
2527 if (uptodate && tree->track_uptodate) {
2528 set_extent_uptodate(tree, start, end, &cached,
2531 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2534 SetPageUptodate(page);
2536 ClearPageUptodate(page);
2540 } while (bvec <= bvec_end);
2546 * this allocates from the btrfs_bioset. We're returning a bio right now
2547 * but you can call btrfs_io_bio for the appropriate container_of magic
2550 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2555 bio = bio_alloc_bioset(gfp_flags, nr_vecs, btrfs_bioset);
2557 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2558 while (!bio && (nr_vecs /= 2)) {
2559 bio = bio_alloc_bioset(gfp_flags,
2560 nr_vecs, btrfs_bioset);
2566 bio->bi_bdev = bdev;
2567 bio->bi_sector = first_sector;
2572 struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
2574 return bio_clone_bioset(bio, gfp_mask, btrfs_bioset);
2578 /* this also allocates from the btrfs_bioset */
2579 struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
2581 return bio_alloc_bioset(gfp_mask, nr_iovecs, btrfs_bioset);
2585 static int __must_check submit_one_bio(int rw, struct bio *bio,
2586 int mirror_num, unsigned long bio_flags)
2589 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2590 struct page *page = bvec->bv_page;
2591 struct extent_io_tree *tree = bio->bi_private;
2594 start = page_offset(page) + bvec->bv_offset;
2596 bio->bi_private = NULL;
2600 if (tree->ops && tree->ops->submit_bio_hook)
2601 ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
2602 mirror_num, bio_flags, start);
2604 btrfsic_submit_bio(rw, bio);
2606 if (bio_flagged(bio, BIO_EOPNOTSUPP))
2612 static int merge_bio(int rw, struct extent_io_tree *tree, struct page *page,
2613 unsigned long offset, size_t size, struct bio *bio,
2614 unsigned long bio_flags)
2617 if (tree->ops && tree->ops->merge_bio_hook)
2618 ret = tree->ops->merge_bio_hook(rw, page, offset, size, bio,
2625 static int submit_extent_page(int rw, struct extent_io_tree *tree,
2626 struct page *page, sector_t sector,
2627 size_t size, unsigned long offset,
2628 struct block_device *bdev,
2629 struct bio **bio_ret,
2630 unsigned long max_pages,
2631 bio_end_io_t end_io_func,
2633 unsigned long prev_bio_flags,
2634 unsigned long bio_flags)
2640 int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
2641 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2642 size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
2644 if (bio_ret && *bio_ret) {
2647 contig = bio->bi_sector == sector;
2649 contig = bio_end_sector(bio) == sector;
2651 if (prev_bio_flags != bio_flags || !contig ||
2652 merge_bio(rw, tree, page, offset, page_size, bio, bio_flags) ||
2653 bio_add_page(bio, page, page_size, offset) < page_size) {
2654 ret = submit_one_bio(rw, bio, mirror_num,
2663 if (this_compressed)
2666 nr = bio_get_nr_vecs(bdev);
2668 bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
2672 bio_add_page(bio, page, page_size, offset);
2673 bio->bi_end_io = end_io_func;
2674 bio->bi_private = tree;
2679 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
2684 static void attach_extent_buffer_page(struct extent_buffer *eb,
2687 if (!PagePrivate(page)) {
2688 SetPagePrivate(page);
2689 page_cache_get(page);
2690 set_page_private(page, (unsigned long)eb);
2692 WARN_ON(page->private != (unsigned long)eb);
2696 void set_page_extent_mapped(struct page *page)
2698 if (!PagePrivate(page)) {
2699 SetPagePrivate(page);
2700 page_cache_get(page);
2701 set_page_private(page, EXTENT_PAGE_PRIVATE);
2706 * basic readpage implementation. Locked extent state structs are inserted
2707 * into the tree that are removed when the IO is done (by the end_io
2709 * XXX JDM: This needs looking at to ensure proper page locking
2711 static int __extent_read_full_page(struct extent_io_tree *tree,
2713 get_extent_t *get_extent,
2714 struct bio **bio, int mirror_num,
2715 unsigned long *bio_flags, int rw)
2717 struct inode *inode = page->mapping->host;
2718 u64 start = page_offset(page);
2719 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2723 u64 last_byte = i_size_read(inode);
2727 struct extent_map *em;
2728 struct block_device *bdev;
2729 struct btrfs_ordered_extent *ordered;
2732 size_t pg_offset = 0;
2734 size_t disk_io_size;
2735 size_t blocksize = inode->i_sb->s_blocksize;
2736 unsigned long this_bio_flag = 0;
2738 set_page_extent_mapped(page);
2740 if (!PageUptodate(page)) {
2741 if (cleancache_get_page(page) == 0) {
2742 BUG_ON(blocksize != PAGE_SIZE);
2749 lock_extent(tree, start, end);
2750 ordered = btrfs_lookup_ordered_extent(inode, start);
2753 unlock_extent(tree, start, end);
2754 btrfs_start_ordered_extent(inode, ordered, 1);
2755 btrfs_put_ordered_extent(ordered);
2758 if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
2760 size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
2763 iosize = PAGE_CACHE_SIZE - zero_offset;
2764 userpage = kmap_atomic(page);
2765 memset(userpage + zero_offset, 0, iosize);
2766 flush_dcache_page(page);
2767 kunmap_atomic(userpage);
2770 while (cur <= end) {
2771 unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
2773 if (cur >= last_byte) {
2775 struct extent_state *cached = NULL;
2777 iosize = PAGE_CACHE_SIZE - pg_offset;
2778 userpage = kmap_atomic(page);
2779 memset(userpage + pg_offset, 0, iosize);
2780 flush_dcache_page(page);
2781 kunmap_atomic(userpage);
2782 set_extent_uptodate(tree, cur, cur + iosize - 1,
2784 unlock_extent_cached(tree, cur, cur + iosize - 1,
2788 em = get_extent(inode, page, pg_offset, cur,
2790 if (IS_ERR_OR_NULL(em)) {
2792 unlock_extent(tree, cur, end);
2795 extent_offset = cur - em->start;
2796 BUG_ON(extent_map_end(em) <= cur);
2799 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2800 this_bio_flag = EXTENT_BIO_COMPRESSED;
2801 extent_set_compress_type(&this_bio_flag,
2805 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2806 cur_end = min(extent_map_end(em) - 1, end);
2807 iosize = ALIGN(iosize, blocksize);
2808 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2809 disk_io_size = em->block_len;
2810 sector = em->block_start >> 9;
2812 sector = (em->block_start + extent_offset) >> 9;
2813 disk_io_size = iosize;
2816 block_start = em->block_start;
2817 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2818 block_start = EXTENT_MAP_HOLE;
2819 free_extent_map(em);
2822 /* we've found a hole, just zero and go on */
2823 if (block_start == EXTENT_MAP_HOLE) {
2825 struct extent_state *cached = NULL;
2827 userpage = kmap_atomic(page);
2828 memset(userpage + pg_offset, 0, iosize);
2829 flush_dcache_page(page);
2830 kunmap_atomic(userpage);
2832 set_extent_uptodate(tree, cur, cur + iosize - 1,
2834 unlock_extent_cached(tree, cur, cur + iosize - 1,
2837 pg_offset += iosize;
2840 /* the get_extent function already copied into the page */
2841 if (test_range_bit(tree, cur, cur_end,
2842 EXTENT_UPTODATE, 1, NULL)) {
2843 check_page_uptodate(tree, page);
2844 unlock_extent(tree, cur, cur + iosize - 1);
2846 pg_offset += iosize;
2849 /* we have an inline extent but it didn't get marked up
2850 * to date. Error out
2852 if (block_start == EXTENT_MAP_INLINE) {
2854 unlock_extent(tree, cur, cur + iosize - 1);
2856 pg_offset += iosize;
2861 ret = submit_extent_page(rw, tree, page,
2862 sector, disk_io_size, pg_offset,
2864 end_bio_extent_readpage, mirror_num,
2869 *bio_flags = this_bio_flag;
2872 unlock_extent(tree, cur, cur + iosize - 1);
2875 pg_offset += iosize;
2879 if (!PageError(page))
2880 SetPageUptodate(page);
2886 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
2887 get_extent_t *get_extent, int mirror_num)
2889 struct bio *bio = NULL;
2890 unsigned long bio_flags = 0;
2893 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
2896 ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
2900 static noinline void update_nr_written(struct page *page,
2901 struct writeback_control *wbc,
2902 unsigned long nr_written)
2904 wbc->nr_to_write -= nr_written;
2905 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
2906 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
2907 page->mapping->writeback_index = page->index + nr_written;
2911 * the writepage semantics are similar to regular writepage. extent
2912 * records are inserted to lock ranges in the tree, and as dirty areas
2913 * are found, they are marked writeback. Then the lock bits are removed
2914 * and the end_io handler clears the writeback ranges
2916 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
2919 struct inode *inode = page->mapping->host;
2920 struct extent_page_data *epd = data;
2921 struct extent_io_tree *tree = epd->tree;
2922 u64 start = page_offset(page);
2924 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2928 u64 last_byte = i_size_read(inode);
2932 struct extent_state *cached_state = NULL;
2933 struct extent_map *em;
2934 struct block_device *bdev;
2937 size_t pg_offset = 0;
2939 loff_t i_size = i_size_read(inode);
2940 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
2946 unsigned long nr_written = 0;
2947 bool fill_delalloc = true;
2949 if (wbc->sync_mode == WB_SYNC_ALL)
2950 write_flags = WRITE_SYNC;
2952 write_flags = WRITE;
2954 trace___extent_writepage(page, inode, wbc);
2956 WARN_ON(!PageLocked(page));
2958 ClearPageError(page);
2960 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2961 if (page->index > end_index ||
2962 (page->index == end_index && !pg_offset)) {
2963 page->mapping->a_ops->invalidatepage(page, 0);
2968 if (page->index == end_index) {
2971 userpage = kmap_atomic(page);
2972 memset(userpage + pg_offset, 0,
2973 PAGE_CACHE_SIZE - pg_offset);
2974 kunmap_atomic(userpage);
2975 flush_dcache_page(page);
2979 set_page_extent_mapped(page);
2981 if (!tree->ops || !tree->ops->fill_delalloc)
2982 fill_delalloc = false;
2984 delalloc_start = start;
2987 if (!epd->extent_locked && fill_delalloc) {
2988 u64 delalloc_to_write = 0;
2990 * make sure the wbc mapping index is at least updated
2993 update_nr_written(page, wbc, 0);
2995 while (delalloc_end < page_end) {
2996 nr_delalloc = find_lock_delalloc_range(inode, tree,
3001 if (nr_delalloc == 0) {
3002 delalloc_start = delalloc_end + 1;
3005 ret = tree->ops->fill_delalloc(inode, page,
3010 /* File system has been set read-only */
3016 * delalloc_end is already one less than the total
3017 * length, so we don't subtract one from
3020 delalloc_to_write += (delalloc_end - delalloc_start +
3023 delalloc_start = delalloc_end + 1;
3025 if (wbc->nr_to_write < delalloc_to_write) {
3028 if (delalloc_to_write < thresh * 2)
3029 thresh = delalloc_to_write;
3030 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3034 /* did the fill delalloc function already unlock and start
3040 * we've unlocked the page, so we can't update
3041 * the mapping's writeback index, just update
3044 wbc->nr_to_write -= nr_written;
3048 if (tree->ops && tree->ops->writepage_start_hook) {
3049 ret = tree->ops->writepage_start_hook(page, start,
3052 /* Fixup worker will requeue */
3054 wbc->pages_skipped++;
3056 redirty_page_for_writepage(wbc, page);
3057 update_nr_written(page, wbc, nr_written);
3065 * we don't want to touch the inode after unlocking the page,
3066 * so we update the mapping writeback index now
3068 update_nr_written(page, wbc, nr_written + 1);
3071 if (last_byte <= start) {
3072 if (tree->ops && tree->ops->writepage_end_io_hook)
3073 tree->ops->writepage_end_io_hook(page, start,
3078 blocksize = inode->i_sb->s_blocksize;
3080 while (cur <= end) {
3081 if (cur >= last_byte) {
3082 if (tree->ops && tree->ops->writepage_end_io_hook)
3083 tree->ops->writepage_end_io_hook(page, cur,
3087 em = epd->get_extent(inode, page, pg_offset, cur,
3089 if (IS_ERR_OR_NULL(em)) {
3094 extent_offset = cur - em->start;
3095 BUG_ON(extent_map_end(em) <= cur);
3097 iosize = min(extent_map_end(em) - cur, end - cur + 1);
3098 iosize = ALIGN(iosize, blocksize);
3099 sector = (em->block_start + extent_offset) >> 9;
3101 block_start = em->block_start;
3102 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3103 free_extent_map(em);
3107 * compressed and inline extents are written through other
3110 if (compressed || block_start == EXTENT_MAP_HOLE ||
3111 block_start == EXTENT_MAP_INLINE) {
3113 * end_io notification does not happen here for
3114 * compressed extents
3116 if (!compressed && tree->ops &&
3117 tree->ops->writepage_end_io_hook)
3118 tree->ops->writepage_end_io_hook(page, cur,
3121 else if (compressed) {
3122 /* we don't want to end_page_writeback on
3123 * a compressed extent. this happens
3130 pg_offset += iosize;
3133 /* leave this out until we have a page_mkwrite call */
3134 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
3135 EXTENT_DIRTY, 0, NULL)) {
3137 pg_offset += iosize;
3141 if (tree->ops && tree->ops->writepage_io_hook) {
3142 ret = tree->ops->writepage_io_hook(page, cur,
3150 unsigned long max_nr = end_index + 1;
3152 set_range_writeback(tree, cur, cur + iosize - 1);
3153 if (!PageWriteback(page)) {
3154 printk(KERN_ERR "btrfs warning page %lu not "
3155 "writeback, cur %llu end %llu\n",
3156 page->index, (unsigned long long)cur,
3157 (unsigned long long)end);
3160 ret = submit_extent_page(write_flags, tree, page,
3161 sector, iosize, pg_offset,
3162 bdev, &epd->bio, max_nr,
3163 end_bio_extent_writepage,
3169 pg_offset += iosize;
3174 /* make sure the mapping tag for page dirty gets cleared */
3175 set_page_writeback(page);
3176 end_page_writeback(page);
3182 /* drop our reference on any cached states */
3183 free_extent_state(cached_state);
3187 static int eb_wait(void *word)
3193 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3195 wait_on_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK, eb_wait,
3196 TASK_UNINTERRUPTIBLE);
3199 static int lock_extent_buffer_for_io(struct extent_buffer *eb,
3200 struct btrfs_fs_info *fs_info,
3201 struct extent_page_data *epd)
3203 unsigned long i, num_pages;
3207 if (!btrfs_try_tree_write_lock(eb)) {
3209 flush_write_bio(epd);
3210 btrfs_tree_lock(eb);
3213 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3214 btrfs_tree_unlock(eb);
3218 flush_write_bio(epd);
3222 wait_on_extent_buffer_writeback(eb);
3223 btrfs_tree_lock(eb);
3224 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3226 btrfs_tree_unlock(eb);
3231 * We need to do this to prevent races in people who check if the eb is
3232 * under IO since we can end up having no IO bits set for a short period
3235 spin_lock(&eb->refs_lock);
3236 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3237 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3238 spin_unlock(&eb->refs_lock);
3239 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3240 __percpu_counter_add(&fs_info->dirty_metadata_bytes,
3242 fs_info->dirty_metadata_batch);
3245 spin_unlock(&eb->refs_lock);
3248 btrfs_tree_unlock(eb);
3253 num_pages = num_extent_pages(eb->start, eb->len);
3254 for (i = 0; i < num_pages; i++) {
3255 struct page *p = extent_buffer_page(eb, i);
3257 if (!trylock_page(p)) {
3259 flush_write_bio(epd);
3269 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3271 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3272 smp_mb__after_clear_bit();
3273 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3276 static void end_bio_extent_buffer_writepage(struct bio *bio, int err)
3278 int uptodate = err == 0;
3279 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
3280 struct extent_buffer *eb;
3284 struct page *page = bvec->bv_page;
3287 eb = (struct extent_buffer *)page->private;
3289 done = atomic_dec_and_test(&eb->io_pages);
3291 if (!uptodate || test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) {
3292 set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3293 ClearPageUptodate(page);
3297 end_page_writeback(page);
3302 end_extent_buffer_writeback(eb);
3303 } while (bvec >= bio->bi_io_vec);
3309 static int write_one_eb(struct extent_buffer *eb,
3310 struct btrfs_fs_info *fs_info,
3311 struct writeback_control *wbc,
3312 struct extent_page_data *epd)
3314 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3315 u64 offset = eb->start;
3316 unsigned long i, num_pages;
3317 unsigned long bio_flags = 0;
3318 int rw = (epd->sync_io ? WRITE_SYNC : WRITE) | REQ_META;
3321 clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3322 num_pages = num_extent_pages(eb->start, eb->len);
3323 atomic_set(&eb->io_pages, num_pages);
3324 if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
3325 bio_flags = EXTENT_BIO_TREE_LOG;
3327 for (i = 0; i < num_pages; i++) {
3328 struct page *p = extent_buffer_page(eb, i);
3330 clear_page_dirty_for_io(p);
3331 set_page_writeback(p);
3332 ret = submit_extent_page(rw, eb->tree, p, offset >> 9,
3333 PAGE_CACHE_SIZE, 0, bdev, &epd->bio,
3334 -1, end_bio_extent_buffer_writepage,
3335 0, epd->bio_flags, bio_flags);
3336 epd->bio_flags = bio_flags;
3338 set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3340 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3341 end_extent_buffer_writeback(eb);
3345 offset += PAGE_CACHE_SIZE;
3346 update_nr_written(p, wbc, 1);
3350 if (unlikely(ret)) {
3351 for (; i < num_pages; i++) {
3352 struct page *p = extent_buffer_page(eb, i);
3360 int btree_write_cache_pages(struct address_space *mapping,
3361 struct writeback_control *wbc)
3363 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3364 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3365 struct extent_buffer *eb, *prev_eb = NULL;
3366 struct extent_page_data epd = {
3370 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3375 int nr_to_write_done = 0;
3376 struct pagevec pvec;
3379 pgoff_t end; /* Inclusive */
3383 pagevec_init(&pvec, 0);
3384 if (wbc->range_cyclic) {
3385 index = mapping->writeback_index; /* Start from prev offset */
3388 index = wbc->range_start >> PAGE_CACHE_SHIFT;
3389 end = wbc->range_end >> PAGE_CACHE_SHIFT;
3392 if (wbc->sync_mode == WB_SYNC_ALL)
3393 tag = PAGECACHE_TAG_TOWRITE;
3395 tag = PAGECACHE_TAG_DIRTY;
3397 if (wbc->sync_mode == WB_SYNC_ALL)
3398 tag_pages_for_writeback(mapping, index, end);
3399 while (!done && !nr_to_write_done && (index <= end) &&
3400 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3401 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3405 for (i = 0; i < nr_pages; i++) {
3406 struct page *page = pvec.pages[i];
3408 if (!PagePrivate(page))
3411 if (!wbc->range_cyclic && page->index > end) {
3416 spin_lock(&mapping->private_lock);
3417 if (!PagePrivate(page)) {
3418 spin_unlock(&mapping->private_lock);
3422 eb = (struct extent_buffer *)page->private;
3425 * Shouldn't happen and normally this would be a BUG_ON
3426 * but no sense in crashing the users box for something
3427 * we can survive anyway.
3430 spin_unlock(&mapping->private_lock);
3435 if (eb == prev_eb) {
3436 spin_unlock(&mapping->private_lock);
3440 ret = atomic_inc_not_zero(&eb->refs);
3441 spin_unlock(&mapping->private_lock);
3446 ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
3448 free_extent_buffer(eb);
3452 ret = write_one_eb(eb, fs_info, wbc, &epd);
3455 free_extent_buffer(eb);
3458 free_extent_buffer(eb);
3461 * the filesystem may choose to bump up nr_to_write.
3462 * We have to make sure to honor the new nr_to_write
3465 nr_to_write_done = wbc->nr_to_write <= 0;
3467 pagevec_release(&pvec);
3470 if (!scanned && !done) {
3472 * We hit the last page and there is more work to be done: wrap
3473 * back to the start of the file
3479 flush_write_bio(&epd);
3484 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3485 * @mapping: address space structure to write
3486 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3487 * @writepage: function called for each page
3488 * @data: data passed to writepage function
3490 * If a page is already under I/O, write_cache_pages() skips it, even
3491 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3492 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3493 * and msync() need to guarantee that all the data which was dirty at the time
3494 * the call was made get new I/O started against them. If wbc->sync_mode is
3495 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3496 * existing IO to complete.
3498 static int extent_write_cache_pages(struct extent_io_tree *tree,
3499 struct address_space *mapping,
3500 struct writeback_control *wbc,
3501 writepage_t writepage, void *data,
3502 void (*flush_fn)(void *))
3504 struct inode *inode = mapping->host;
3507 int nr_to_write_done = 0;
3508 struct pagevec pvec;
3511 pgoff_t end; /* Inclusive */
3516 * We have to hold onto the inode so that ordered extents can do their
3517 * work when the IO finishes. The alternative to this is failing to add
3518 * an ordered extent if the igrab() fails there and that is a huge pain
3519 * to deal with, so instead just hold onto the inode throughout the
3520 * writepages operation. If it fails here we are freeing up the inode
3521 * anyway and we'd rather not waste our time writing out stuff that is
3522 * going to be truncated anyway.
3527 pagevec_init(&pvec, 0);
3528 if (wbc->range_cyclic) {
3529 index = mapping->writeback_index; /* Start from prev offset */
3532 index = wbc->range_start >> PAGE_CACHE_SHIFT;
3533 end = wbc->range_end >> PAGE_CACHE_SHIFT;
3536 if (wbc->sync_mode == WB_SYNC_ALL)
3537 tag = PAGECACHE_TAG_TOWRITE;
3539 tag = PAGECACHE_TAG_DIRTY;
3541 if (wbc->sync_mode == WB_SYNC_ALL)
3542 tag_pages_for_writeback(mapping, index, end);
3543 while (!done && !nr_to_write_done && (index <= end) &&
3544 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3545 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3549 for (i = 0; i < nr_pages; i++) {
3550 struct page *page = pvec.pages[i];
3553 * At this point we hold neither mapping->tree_lock nor
3554 * lock on the page itself: the page may be truncated or
3555 * invalidated (changing page->mapping to NULL), or even
3556 * swizzled back from swapper_space to tmpfs file
3559 if (!trylock_page(page)) {
3564 if (unlikely(page->mapping != mapping)) {
3569 if (!wbc->range_cyclic && page->index > end) {
3575 if (wbc->sync_mode != WB_SYNC_NONE) {
3576 if (PageWriteback(page))
3578 wait_on_page_writeback(page);
3581 if (PageWriteback(page) ||
3582 !clear_page_dirty_for_io(page)) {
3587 ret = (*writepage)(page, wbc, data);
3589 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
3597 * the filesystem may choose to bump up nr_to_write.
3598 * We have to make sure to honor the new nr_to_write
3601 nr_to_write_done = wbc->nr_to_write <= 0;
3603 pagevec_release(&pvec);
3606 if (!scanned && !done) {
3608 * We hit the last page and there is more work to be done: wrap
3609 * back to the start of the file
3615 btrfs_add_delayed_iput(inode);
3619 static void flush_epd_write_bio(struct extent_page_data *epd)
3628 ret = submit_one_bio(rw, epd->bio, 0, epd->bio_flags);
3629 BUG_ON(ret < 0); /* -ENOMEM */
3634 static noinline void flush_write_bio(void *data)
3636 struct extent_page_data *epd = data;
3637 flush_epd_write_bio(epd);
3640 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
3641 get_extent_t *get_extent,
3642 struct writeback_control *wbc)
3645 struct extent_page_data epd = {
3648 .get_extent = get_extent,
3650 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3654 ret = __extent_writepage(page, wbc, &epd);
3656 flush_epd_write_bio(&epd);
3660 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
3661 u64 start, u64 end, get_extent_t *get_extent,
3665 struct address_space *mapping = inode->i_mapping;
3667 unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
3670 struct extent_page_data epd = {
3673 .get_extent = get_extent,
3675 .sync_io = mode == WB_SYNC_ALL,
3678 struct writeback_control wbc_writepages = {
3680 .nr_to_write = nr_pages * 2,
3681 .range_start = start,
3682 .range_end = end + 1,
3685 while (start <= end) {
3686 page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
3687 if (clear_page_dirty_for_io(page))
3688 ret = __extent_writepage(page, &wbc_writepages, &epd);
3690 if (tree->ops && tree->ops->writepage_end_io_hook)
3691 tree->ops->writepage_end_io_hook(page, start,
3692 start + PAGE_CACHE_SIZE - 1,
3696 page_cache_release(page);
3697 start += PAGE_CACHE_SIZE;
3700 flush_epd_write_bio(&epd);
3704 int extent_writepages(struct extent_io_tree *tree,
3705 struct address_space *mapping,
3706 get_extent_t *get_extent,
3707 struct writeback_control *wbc)
3710 struct extent_page_data epd = {
3713 .get_extent = get_extent,
3715 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3719 ret = extent_write_cache_pages(tree, mapping, wbc,
3720 __extent_writepage, &epd,
3722 flush_epd_write_bio(&epd);
3726 int extent_readpages(struct extent_io_tree *tree,
3727 struct address_space *mapping,
3728 struct list_head *pages, unsigned nr_pages,
3729 get_extent_t get_extent)
3731 struct bio *bio = NULL;
3733 unsigned long bio_flags = 0;
3734 struct page *pagepool[16];
3739 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
3740 page = list_entry(pages->prev, struct page, lru);
3742 prefetchw(&page->flags);
3743 list_del(&page->lru);
3744 if (add_to_page_cache_lru(page, mapping,
3745 page->index, GFP_NOFS)) {
3746 page_cache_release(page);
3750 pagepool[nr++] = page;
3751 if (nr < ARRAY_SIZE(pagepool))
3753 for (i = 0; i < nr; i++) {
3754 __extent_read_full_page(tree, pagepool[i], get_extent,
3755 &bio, 0, &bio_flags, READ);
3756 page_cache_release(pagepool[i]);
3760 for (i = 0; i < nr; i++) {
3761 __extent_read_full_page(tree, pagepool[i], get_extent,
3762 &bio, 0, &bio_flags, READ);
3763 page_cache_release(pagepool[i]);
3766 BUG_ON(!list_empty(pages));
3768 return submit_one_bio(READ, bio, 0, bio_flags);
3773 * basic invalidatepage code, this waits on any locked or writeback
3774 * ranges corresponding to the page, and then deletes any extent state
3775 * records from the tree
3777 int extent_invalidatepage(struct extent_io_tree *tree,
3778 struct page *page, unsigned long offset)
3780 struct extent_state *cached_state = NULL;
3781 u64 start = page_offset(page);
3782 u64 end = start + PAGE_CACHE_SIZE - 1;
3783 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
3785 start += ALIGN(offset, blocksize);
3789 lock_extent_bits(tree, start, end, 0, &cached_state);
3790 wait_on_page_writeback(page);
3791 clear_extent_bit(tree, start, end,
3792 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
3793 EXTENT_DO_ACCOUNTING,
3794 1, 1, &cached_state, GFP_NOFS);
3799 * a helper for releasepage, this tests for areas of the page that
3800 * are locked or under IO and drops the related state bits if it is safe
3803 static int try_release_extent_state(struct extent_map_tree *map,
3804 struct extent_io_tree *tree,
3805 struct page *page, gfp_t mask)
3807 u64 start = page_offset(page);
3808 u64 end = start + PAGE_CACHE_SIZE - 1;
3811 if (test_range_bit(tree, start, end,
3812 EXTENT_IOBITS, 0, NULL))
3815 if ((mask & GFP_NOFS) == GFP_NOFS)
3818 * at this point we can safely clear everything except the
3819 * locked bit and the nodatasum bit
3821 ret = clear_extent_bit(tree, start, end,
3822 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
3825 /* if clear_extent_bit failed for enomem reasons,
3826 * we can't allow the release to continue.
3837 * a helper for releasepage. As long as there are no locked extents
3838 * in the range corresponding to the page, both state records and extent
3839 * map records are removed
3841 int try_release_extent_mapping(struct extent_map_tree *map,
3842 struct extent_io_tree *tree, struct page *page,
3845 struct extent_map *em;
3846 u64 start = page_offset(page);
3847 u64 end = start + PAGE_CACHE_SIZE - 1;
3849 if ((mask & __GFP_WAIT) &&
3850 page->mapping->host->i_size > 16 * 1024 * 1024) {
3852 while (start <= end) {
3853 len = end - start + 1;
3854 write_lock(&map->lock);
3855 em = lookup_extent_mapping(map, start, len);
3857 write_unlock(&map->lock);
3860 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
3861 em->start != start) {
3862 write_unlock(&map->lock);
3863 free_extent_map(em);
3866 if (!test_range_bit(tree, em->start,
3867 extent_map_end(em) - 1,
3868 EXTENT_LOCKED | EXTENT_WRITEBACK,
3870 remove_extent_mapping(map, em);
3871 /* once for the rb tree */
3872 free_extent_map(em);
3874 start = extent_map_end(em);
3875 write_unlock(&map->lock);
3878 free_extent_map(em);
3881 return try_release_extent_state(map, tree, page, mask);
3885 * helper function for fiemap, which doesn't want to see any holes.
3886 * This maps until we find something past 'last'
3888 static struct extent_map *get_extent_skip_holes(struct inode *inode,
3891 get_extent_t *get_extent)
3893 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
3894 struct extent_map *em;
3901 len = last - offset;
3904 len = ALIGN(len, sectorsize);
3905 em = get_extent(inode, NULL, 0, offset, len, 0);
3906 if (IS_ERR_OR_NULL(em))
3909 /* if this isn't a hole return it */
3910 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
3911 em->block_start != EXTENT_MAP_HOLE) {
3915 /* this is a hole, advance to the next extent */
3916 offset = extent_map_end(em);
3917 free_extent_map(em);
3924 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3925 __u64 start, __u64 len, get_extent_t *get_extent)
3929 u64 max = start + len;
3933 u64 last_for_get_extent = 0;
3935 u64 isize = i_size_read(inode);
3936 struct btrfs_key found_key;
3937 struct extent_map *em = NULL;
3938 struct extent_state *cached_state = NULL;
3939 struct btrfs_path *path;
3940 struct btrfs_file_extent_item *item;
3945 unsigned long emflags;
3950 path = btrfs_alloc_path();
3953 path->leave_spinning = 1;
3955 start = ALIGN(start, BTRFS_I(inode)->root->sectorsize);
3956 len = ALIGN(len, BTRFS_I(inode)->root->sectorsize);
3959 * lookup the last file extent. We're not using i_size here
3960 * because there might be preallocation past i_size
3962 ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
3963 path, btrfs_ino(inode), -1, 0);
3965 btrfs_free_path(path);
3970 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3971 struct btrfs_file_extent_item);
3972 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
3973 found_type = btrfs_key_type(&found_key);
3975 /* No extents, but there might be delalloc bits */
3976 if (found_key.objectid != btrfs_ino(inode) ||
3977 found_type != BTRFS_EXTENT_DATA_KEY) {
3978 /* have to trust i_size as the end */
3980 last_for_get_extent = isize;
3983 * remember the start of the last extent. There are a
3984 * bunch of different factors that go into the length of the
3985 * extent, so its much less complex to remember where it started
3987 last = found_key.offset;
3988 last_for_get_extent = last + 1;
3990 btrfs_free_path(path);
3993 * we might have some extents allocated but more delalloc past those
3994 * extents. so, we trust isize unless the start of the last extent is
3999 last_for_get_extent = isize;
4002 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1, 0,
4005 em = get_extent_skip_holes(inode, start, last_for_get_extent,
4015 u64 offset_in_extent;
4017 /* break if the extent we found is outside the range */
4018 if (em->start >= max || extent_map_end(em) < off)
4022 * get_extent may return an extent that starts before our
4023 * requested range. We have to make sure the ranges
4024 * we return to fiemap always move forward and don't
4025 * overlap, so adjust the offsets here
4027 em_start = max(em->start, off);
4030 * record the offset from the start of the extent
4031 * for adjusting the disk offset below
4033 offset_in_extent = em_start - em->start;
4034 em_end = extent_map_end(em);
4035 em_len = em_end - em_start;
4036 emflags = em->flags;
4041 * bump off for our next call to get_extent
4043 off = extent_map_end(em);
4047 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4049 flags |= FIEMAP_EXTENT_LAST;
4050 } else if (em->block_start == EXTENT_MAP_INLINE) {
4051 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4052 FIEMAP_EXTENT_NOT_ALIGNED);
4053 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4054 flags |= (FIEMAP_EXTENT_DELALLOC |
4055 FIEMAP_EXTENT_UNKNOWN);
4057 disko = em->block_start + offset_in_extent;
4059 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4060 flags |= FIEMAP_EXTENT_ENCODED;
4062 free_extent_map(em);
4064 if ((em_start >= last) || em_len == (u64)-1 ||
4065 (last == (u64)-1 && isize <= em_end)) {
4066 flags |= FIEMAP_EXTENT_LAST;
4070 /* now scan forward to see if this is really the last extent. */
4071 em = get_extent_skip_holes(inode, off, last_for_get_extent,
4078 flags |= FIEMAP_EXTENT_LAST;
4081 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
4087 free_extent_map(em);
4089 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4090 &cached_state, GFP_NOFS);
4094 static void __free_extent_buffer(struct extent_buffer *eb)
4096 btrfs_leak_debug_del(&eb->leak_list);
4097 kmem_cache_free(extent_buffer_cache, eb);
4100 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
4105 struct extent_buffer *eb = NULL;
4107 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
4114 rwlock_init(&eb->lock);
4115 atomic_set(&eb->write_locks, 0);
4116 atomic_set(&eb->read_locks, 0);
4117 atomic_set(&eb->blocking_readers, 0);
4118 atomic_set(&eb->blocking_writers, 0);
4119 atomic_set(&eb->spinning_readers, 0);
4120 atomic_set(&eb->spinning_writers, 0);
4121 eb->lock_nested = 0;
4122 init_waitqueue_head(&eb->write_lock_wq);
4123 init_waitqueue_head(&eb->read_lock_wq);
4125 btrfs_leak_debug_add(&eb->leak_list, &buffers);
4127 spin_lock_init(&eb->refs_lock);
4128 atomic_set(&eb->refs, 1);
4129 atomic_set(&eb->io_pages, 0);
4132 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4134 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4135 > MAX_INLINE_EXTENT_BUFFER_SIZE);
4136 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
4141 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4145 struct extent_buffer *new;
4146 unsigned long num_pages = num_extent_pages(src->start, src->len);
4148 new = __alloc_extent_buffer(NULL, src->start, src->len, GFP_ATOMIC);
4152 for (i = 0; i < num_pages; i++) {
4153 p = alloc_page(GFP_ATOMIC);
4155 attach_extent_buffer_page(new, p);
4156 WARN_ON(PageDirty(p));
4161 copy_extent_buffer(new, src, 0, 0, src->len);
4162 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4163 set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
4168 struct extent_buffer *alloc_dummy_extent_buffer(u64 start, unsigned long len)
4170 struct extent_buffer *eb;
4171 unsigned long num_pages = num_extent_pages(0, len);
4174 eb = __alloc_extent_buffer(NULL, start, len, GFP_ATOMIC);
4178 for (i = 0; i < num_pages; i++) {
4179 eb->pages[i] = alloc_page(GFP_ATOMIC);
4183 set_extent_buffer_uptodate(eb);
4184 btrfs_set_header_nritems(eb, 0);
4185 set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4190 __free_page(eb->pages[i - 1]);
4191 __free_extent_buffer(eb);
4195 static int extent_buffer_under_io(struct extent_buffer *eb)
4197 return (atomic_read(&eb->io_pages) ||
4198 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4199 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4203 * Helper for releasing extent buffer page.
4205 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
4206 unsigned long start_idx)
4208 unsigned long index;
4209 unsigned long num_pages;
4211 int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4213 BUG_ON(extent_buffer_under_io(eb));
4215 num_pages = num_extent_pages(eb->start, eb->len);
4216 index = start_idx + num_pages;
4217 if (start_idx >= index)
4222 page = extent_buffer_page(eb, index);
4223 if (page && mapped) {
4224 spin_lock(&page->mapping->private_lock);
4226 * We do this since we'll remove the pages after we've
4227 * removed the eb from the radix tree, so we could race
4228 * and have this page now attached to the new eb. So
4229 * only clear page_private if it's still connected to
4232 if (PagePrivate(page) &&
4233 page->private == (unsigned long)eb) {
4234 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4235 BUG_ON(PageDirty(page));
4236 BUG_ON(PageWriteback(page));
4238 * We need to make sure we haven't be attached
4241 ClearPagePrivate(page);
4242 set_page_private(page, 0);
4243 /* One for the page private */
4244 page_cache_release(page);
4246 spin_unlock(&page->mapping->private_lock);
4250 /* One for when we alloced the page */
4251 page_cache_release(page);
4253 } while (index != start_idx);
4257 * Helper for releasing the extent buffer.
4259 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4261 btrfs_release_extent_buffer_page(eb, 0);
4262 __free_extent_buffer(eb);
4265 static void check_buffer_tree_ref(struct extent_buffer *eb)
4268 /* the ref bit is tricky. We have to make sure it is set
4269 * if we have the buffer dirty. Otherwise the
4270 * code to free a buffer can end up dropping a dirty
4273 * Once the ref bit is set, it won't go away while the
4274 * buffer is dirty or in writeback, and it also won't
4275 * go away while we have the reference count on the
4278 * We can't just set the ref bit without bumping the
4279 * ref on the eb because free_extent_buffer might
4280 * see the ref bit and try to clear it. If this happens
4281 * free_extent_buffer might end up dropping our original
4282 * ref by mistake and freeing the page before we are able
4283 * to add one more ref.
4285 * So bump the ref count first, then set the bit. If someone
4286 * beat us to it, drop the ref we added.
4288 refs = atomic_read(&eb->refs);
4289 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4292 spin_lock(&eb->refs_lock);
4293 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4294 atomic_inc(&eb->refs);
4295 spin_unlock(&eb->refs_lock);
4298 static void mark_extent_buffer_accessed(struct extent_buffer *eb)
4300 unsigned long num_pages, i;
4302 check_buffer_tree_ref(eb);
4304 num_pages = num_extent_pages(eb->start, eb->len);
4305 for (i = 0; i < num_pages; i++) {
4306 struct page *p = extent_buffer_page(eb, i);
4307 mark_page_accessed(p);
4311 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
4312 u64 start, unsigned long len)
4314 unsigned long num_pages = num_extent_pages(start, len);
4316 unsigned long index = start >> PAGE_CACHE_SHIFT;
4317 struct extent_buffer *eb;
4318 struct extent_buffer *exists = NULL;
4320 struct address_space *mapping = tree->mapping;
4325 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4326 if (eb && atomic_inc_not_zero(&eb->refs)) {
4328 mark_extent_buffer_accessed(eb);
4333 eb = __alloc_extent_buffer(tree, start, len, GFP_NOFS);
4337 for (i = 0; i < num_pages; i++, index++) {
4338 p = find_or_create_page(mapping, index, GFP_NOFS);
4342 spin_lock(&mapping->private_lock);
4343 if (PagePrivate(p)) {
4345 * We could have already allocated an eb for this page
4346 * and attached one so lets see if we can get a ref on
4347 * the existing eb, and if we can we know it's good and
4348 * we can just return that one, else we know we can just
4349 * overwrite page->private.
4351 exists = (struct extent_buffer *)p->private;
4352 if (atomic_inc_not_zero(&exists->refs)) {
4353 spin_unlock(&mapping->private_lock);
4355 page_cache_release(p);
4356 mark_extent_buffer_accessed(exists);
4361 * Do this so attach doesn't complain and we need to
4362 * drop the ref the old guy had.
4364 ClearPagePrivate(p);
4365 WARN_ON(PageDirty(p));
4366 page_cache_release(p);
4368 attach_extent_buffer_page(eb, p);
4369 spin_unlock(&mapping->private_lock);
4370 WARN_ON(PageDirty(p));
4371 mark_page_accessed(p);
4373 if (!PageUptodate(p))
4377 * see below about how we avoid a nasty race with release page
4378 * and why we unlock later
4382 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4384 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
4388 spin_lock(&tree->buffer_lock);
4389 ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
4390 if (ret == -EEXIST) {
4391 exists = radix_tree_lookup(&tree->buffer,
4392 start >> PAGE_CACHE_SHIFT);
4393 if (!atomic_inc_not_zero(&exists->refs)) {
4394 spin_unlock(&tree->buffer_lock);
4395 radix_tree_preload_end();
4399 spin_unlock(&tree->buffer_lock);
4400 radix_tree_preload_end();
4401 mark_extent_buffer_accessed(exists);
4404 /* add one reference for the tree */
4405 check_buffer_tree_ref(eb);
4406 spin_unlock(&tree->buffer_lock);
4407 radix_tree_preload_end();
4410 * there is a race where release page may have
4411 * tried to find this extent buffer in the radix
4412 * but failed. It will tell the VM it is safe to
4413 * reclaim the, and it will clear the page private bit.
4414 * We must make sure to set the page private bit properly
4415 * after the extent buffer is in the radix tree so
4416 * it doesn't get lost
4418 SetPageChecked(eb->pages[0]);
4419 for (i = 1; i < num_pages; i++) {
4420 p = extent_buffer_page(eb, i);
4421 ClearPageChecked(p);
4424 unlock_page(eb->pages[0]);
4428 for (i = 0; i < num_pages; i++) {
4430 unlock_page(eb->pages[i]);
4433 WARN_ON(!atomic_dec_and_test(&eb->refs));
4434 btrfs_release_extent_buffer(eb);
4438 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
4439 u64 start, unsigned long len)
4441 struct extent_buffer *eb;
4444 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4445 if (eb && atomic_inc_not_zero(&eb->refs)) {
4447 mark_extent_buffer_accessed(eb);
4455 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
4457 struct extent_buffer *eb =
4458 container_of(head, struct extent_buffer, rcu_head);
4460 __free_extent_buffer(eb);
4463 /* Expects to have eb->eb_lock already held */
4464 static int release_extent_buffer(struct extent_buffer *eb)
4466 WARN_ON(atomic_read(&eb->refs) == 0);
4467 if (atomic_dec_and_test(&eb->refs)) {
4468 if (test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags)) {
4469 spin_unlock(&eb->refs_lock);
4471 struct extent_io_tree *tree = eb->tree;
4473 spin_unlock(&eb->refs_lock);
4475 spin_lock(&tree->buffer_lock);
4476 radix_tree_delete(&tree->buffer,
4477 eb->start >> PAGE_CACHE_SHIFT);
4478 spin_unlock(&tree->buffer_lock);
4481 /* Should be safe to release our pages at this point */
4482 btrfs_release_extent_buffer_page(eb, 0);
4483 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
4486 spin_unlock(&eb->refs_lock);
4491 void free_extent_buffer(struct extent_buffer *eb)
4499 refs = atomic_read(&eb->refs);
4502 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
4507 spin_lock(&eb->refs_lock);
4508 if (atomic_read(&eb->refs) == 2 &&
4509 test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
4510 atomic_dec(&eb->refs);
4512 if (atomic_read(&eb->refs) == 2 &&
4513 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
4514 !extent_buffer_under_io(eb) &&
4515 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4516 atomic_dec(&eb->refs);
4519 * I know this is terrible, but it's temporary until we stop tracking
4520 * the uptodate bits and such for the extent buffers.
4522 release_extent_buffer(eb);
4525 void free_extent_buffer_stale(struct extent_buffer *eb)
4530 spin_lock(&eb->refs_lock);
4531 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
4533 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
4534 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4535 atomic_dec(&eb->refs);
4536 release_extent_buffer(eb);
4539 void clear_extent_buffer_dirty(struct extent_buffer *eb)
4542 unsigned long num_pages;
4545 num_pages = num_extent_pages(eb->start, eb->len);
4547 for (i = 0; i < num_pages; i++) {
4548 page = extent_buffer_page(eb, i);
4549 if (!PageDirty(page))
4553 WARN_ON(!PagePrivate(page));
4555 clear_page_dirty_for_io(page);
4556 spin_lock_irq(&page->mapping->tree_lock);
4557 if (!PageDirty(page)) {
4558 radix_tree_tag_clear(&page->mapping->page_tree,
4560 PAGECACHE_TAG_DIRTY);
4562 spin_unlock_irq(&page->mapping->tree_lock);
4563 ClearPageError(page);
4566 WARN_ON(atomic_read(&eb->refs) == 0);
4569 int set_extent_buffer_dirty(struct extent_buffer *eb)
4572 unsigned long num_pages;
4575 check_buffer_tree_ref(eb);
4577 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
4579 num_pages = num_extent_pages(eb->start, eb->len);
4580 WARN_ON(atomic_read(&eb->refs) == 0);
4581 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
4583 for (i = 0; i < num_pages; i++)
4584 set_page_dirty(extent_buffer_page(eb, i));
4588 int clear_extent_buffer_uptodate(struct extent_buffer *eb)
4592 unsigned long num_pages;
4594 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4595 num_pages = num_extent_pages(eb->start, eb->len);
4596 for (i = 0; i < num_pages; i++) {
4597 page = extent_buffer_page(eb, i);
4599 ClearPageUptodate(page);
4604 int set_extent_buffer_uptodate(struct extent_buffer *eb)
4608 unsigned long num_pages;
4610 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4611 num_pages = num_extent_pages(eb->start, eb->len);
4612 for (i = 0; i < num_pages; i++) {
4613 page = extent_buffer_page(eb, i);
4614 SetPageUptodate(page);
4619 int extent_buffer_uptodate(struct extent_buffer *eb)
4621 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4624 int read_extent_buffer_pages(struct extent_io_tree *tree,
4625 struct extent_buffer *eb, u64 start, int wait,
4626 get_extent_t *get_extent, int mirror_num)
4629 unsigned long start_i;
4633 int locked_pages = 0;
4634 int all_uptodate = 1;
4635 unsigned long num_pages;
4636 unsigned long num_reads = 0;
4637 struct bio *bio = NULL;
4638 unsigned long bio_flags = 0;
4640 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
4644 WARN_ON(start < eb->start);
4645 start_i = (start >> PAGE_CACHE_SHIFT) -
4646 (eb->start >> PAGE_CACHE_SHIFT);
4651 num_pages = num_extent_pages(eb->start, eb->len);
4652 for (i = start_i; i < num_pages; i++) {
4653 page = extent_buffer_page(eb, i);
4654 if (wait == WAIT_NONE) {
4655 if (!trylock_page(page))
4661 if (!PageUptodate(page)) {
4668 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4672 clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
4673 eb->read_mirror = 0;
4674 atomic_set(&eb->io_pages, num_reads);
4675 for (i = start_i; i < num_pages; i++) {
4676 page = extent_buffer_page(eb, i);
4677 if (!PageUptodate(page)) {
4678 ClearPageError(page);
4679 err = __extent_read_full_page(tree, page,
4681 mirror_num, &bio_flags,
4691 err = submit_one_bio(READ | REQ_META, bio, mirror_num,
4697 if (ret || wait != WAIT_COMPLETE)
4700 for (i = start_i; i < num_pages; i++) {
4701 page = extent_buffer_page(eb, i);
4702 wait_on_page_locked(page);
4703 if (!PageUptodate(page))
4711 while (locked_pages > 0) {
4712 page = extent_buffer_page(eb, i);
4720 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
4721 unsigned long start,
4728 char *dst = (char *)dstv;
4729 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4730 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4732 WARN_ON(start > eb->len);
4733 WARN_ON(start + len > eb->start + eb->len);
4735 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4738 page = extent_buffer_page(eb, i);
4740 cur = min(len, (PAGE_CACHE_SIZE - offset));
4741 kaddr = page_address(page);
4742 memcpy(dst, kaddr + offset, cur);
4751 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
4752 unsigned long min_len, char **map,
4753 unsigned long *map_start,
4754 unsigned long *map_len)
4756 size_t offset = start & (PAGE_CACHE_SIZE - 1);
4759 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4760 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4761 unsigned long end_i = (start_offset + start + min_len - 1) >>
4768 offset = start_offset;
4772 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
4775 if (start + min_len > eb->len) {
4776 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
4777 "wanted %lu %lu\n", (unsigned long long)eb->start,
4778 eb->len, start, min_len);
4782 p = extent_buffer_page(eb, i);
4783 kaddr = page_address(p);
4784 *map = kaddr + offset;
4785 *map_len = PAGE_CACHE_SIZE - offset;
4789 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
4790 unsigned long start,
4797 char *ptr = (char *)ptrv;
4798 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4799 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4802 WARN_ON(start > eb->len);
4803 WARN_ON(start + len > eb->start + eb->len);
4805 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4808 page = extent_buffer_page(eb, i);
4810 cur = min(len, (PAGE_CACHE_SIZE - offset));
4812 kaddr = page_address(page);
4813 ret = memcmp(ptr, kaddr + offset, cur);
4825 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
4826 unsigned long start, unsigned long len)
4832 char *src = (char *)srcv;
4833 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4834 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4836 WARN_ON(start > eb->len);
4837 WARN_ON(start + len > eb->start + eb->len);
4839 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4842 page = extent_buffer_page(eb, i);
4843 WARN_ON(!PageUptodate(page));
4845 cur = min(len, PAGE_CACHE_SIZE - offset);
4846 kaddr = page_address(page);
4847 memcpy(kaddr + offset, src, cur);
4856 void memset_extent_buffer(struct extent_buffer *eb, char c,
4857 unsigned long start, unsigned long len)
4863 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4864 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4866 WARN_ON(start > eb->len);
4867 WARN_ON(start + len > eb->start + eb->len);
4869 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4872 page = extent_buffer_page(eb, i);
4873 WARN_ON(!PageUptodate(page));
4875 cur = min(len, PAGE_CACHE_SIZE - offset);
4876 kaddr = page_address(page);
4877 memset(kaddr + offset, c, cur);
4885 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
4886 unsigned long dst_offset, unsigned long src_offset,
4889 u64 dst_len = dst->len;
4894 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4895 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4897 WARN_ON(src->len != dst_len);
4899 offset = (start_offset + dst_offset) &
4900 ((unsigned long)PAGE_CACHE_SIZE - 1);
4903 page = extent_buffer_page(dst, i);
4904 WARN_ON(!PageUptodate(page));
4906 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
4908 kaddr = page_address(page);
4909 read_extent_buffer(src, kaddr + offset, src_offset, cur);
4918 static void move_pages(struct page *dst_page, struct page *src_page,
4919 unsigned long dst_off, unsigned long src_off,
4922 char *dst_kaddr = page_address(dst_page);
4923 if (dst_page == src_page) {
4924 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
4926 char *src_kaddr = page_address(src_page);
4927 char *p = dst_kaddr + dst_off + len;
4928 char *s = src_kaddr + src_off + len;
4935 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
4937 unsigned long distance = (src > dst) ? src - dst : dst - src;
4938 return distance < len;
4941 static void copy_pages(struct page *dst_page, struct page *src_page,
4942 unsigned long dst_off, unsigned long src_off,
4945 char *dst_kaddr = page_address(dst_page);
4947 int must_memmove = 0;
4949 if (dst_page != src_page) {
4950 src_kaddr = page_address(src_page);
4952 src_kaddr = dst_kaddr;
4953 if (areas_overlap(src_off, dst_off, len))
4958 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
4960 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
4963 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
4964 unsigned long src_offset, unsigned long len)
4967 size_t dst_off_in_page;
4968 size_t src_off_in_page;
4969 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4970 unsigned long dst_i;
4971 unsigned long src_i;
4973 if (src_offset + len > dst->len) {
4974 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4975 "len %lu dst len %lu\n", src_offset, len, dst->len);
4978 if (dst_offset + len > dst->len) {
4979 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4980 "len %lu dst len %lu\n", dst_offset, len, dst->len);
4985 dst_off_in_page = (start_offset + dst_offset) &
4986 ((unsigned long)PAGE_CACHE_SIZE - 1);
4987 src_off_in_page = (start_offset + src_offset) &
4988 ((unsigned long)PAGE_CACHE_SIZE - 1);
4990 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4991 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
4993 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
4995 cur = min_t(unsigned long, cur,
4996 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
4998 copy_pages(extent_buffer_page(dst, dst_i),
4999 extent_buffer_page(dst, src_i),
5000 dst_off_in_page, src_off_in_page, cur);
5008 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5009 unsigned long src_offset, unsigned long len)
5012 size_t dst_off_in_page;
5013 size_t src_off_in_page;
5014 unsigned long dst_end = dst_offset + len - 1;
5015 unsigned long src_end = src_offset + len - 1;
5016 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
5017 unsigned long dst_i;
5018 unsigned long src_i;
5020 if (src_offset + len > dst->len) {
5021 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
5022 "len %lu len %lu\n", src_offset, len, dst->len);
5025 if (dst_offset + len > dst->len) {
5026 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
5027 "len %lu len %lu\n", dst_offset, len, dst->len);
5030 if (dst_offset < src_offset) {
5031 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
5035 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
5036 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
5038 dst_off_in_page = (start_offset + dst_end) &
5039 ((unsigned long)PAGE_CACHE_SIZE - 1);
5040 src_off_in_page = (start_offset + src_end) &
5041 ((unsigned long)PAGE_CACHE_SIZE - 1);
5043 cur = min_t(unsigned long, len, src_off_in_page + 1);
5044 cur = min(cur, dst_off_in_page + 1);
5045 move_pages(extent_buffer_page(dst, dst_i),
5046 extent_buffer_page(dst, src_i),
5047 dst_off_in_page - cur + 1,
5048 src_off_in_page - cur + 1, cur);
5056 int try_release_extent_buffer(struct page *page)
5058 struct extent_buffer *eb;
5061 * We need to make sure noboody is attaching this page to an eb right
5064 spin_lock(&page->mapping->private_lock);
5065 if (!PagePrivate(page)) {
5066 spin_unlock(&page->mapping->private_lock);
5070 eb = (struct extent_buffer *)page->private;
5074 * This is a little awful but should be ok, we need to make sure that
5075 * the eb doesn't disappear out from under us while we're looking at
5078 spin_lock(&eb->refs_lock);
5079 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5080 spin_unlock(&eb->refs_lock);
5081 spin_unlock(&page->mapping->private_lock);
5084 spin_unlock(&page->mapping->private_lock);
5087 * If tree ref isn't set then we know the ref on this eb is a real ref,
5088 * so just return, this page will likely be freed soon anyway.
5090 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
5091 spin_unlock(&eb->refs_lock);
5095 return release_extent_buffer(eb);