1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/module.h>
8 #include <linux/spinlock.h>
9 #include <linux/blkdev.h>
10 #include <linux/swap.h>
11 #include <linux/writeback.h>
12 #include <linux/pagevec.h>
13 #include <linux/prefetch.h>
14 #include <linux/cleancache.h>
15 #include "extent_io.h"
16 #include "extent_map.h"
19 #include "btrfs_inode.h"
21 #include "check-integrity.h"
23 #include "rcu-string.h"
25 static struct kmem_cache *extent_state_cache;
26 static struct kmem_cache *extent_buffer_cache;
28 static LIST_HEAD(buffers);
29 static LIST_HEAD(states);
33 static DEFINE_SPINLOCK(leak_lock);
36 #define BUFFER_LRU_MAX 64
41 struct rb_node rb_node;
44 struct extent_page_data {
46 struct extent_io_tree *tree;
47 get_extent_t *get_extent;
48 unsigned long bio_flags;
50 /* tells writepage not to lock the state bits for this range
51 * it still does the unlocking
53 unsigned int extent_locked:1;
55 /* tells the submit_bio code to use a WRITE_SYNC */
56 unsigned int sync_io:1;
59 static noinline void flush_write_bio(void *data);
60 static inline struct btrfs_fs_info *
61 tree_fs_info(struct extent_io_tree *tree)
63 return btrfs_sb(tree->mapping->host->i_sb);
66 int __init extent_io_init(void)
68 extent_state_cache = kmem_cache_create("btrfs_extent_state",
69 sizeof(struct extent_state), 0,
70 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
71 if (!extent_state_cache)
74 extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
75 sizeof(struct extent_buffer), 0,
76 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
77 if (!extent_buffer_cache)
78 goto free_state_cache;
82 kmem_cache_destroy(extent_state_cache);
86 void extent_io_exit(void)
88 struct extent_state *state;
89 struct extent_buffer *eb;
91 while (!list_empty(&states)) {
92 state = list_entry(states.next, struct extent_state, leak_list);
93 printk(KERN_ERR "btrfs state leak: start %llu end %llu "
94 "state %lu in tree %p refs %d\n",
95 (unsigned long long)state->start,
96 (unsigned long long)state->end,
97 state->state, state->tree, atomic_read(&state->refs));
98 list_del(&state->leak_list);
99 kmem_cache_free(extent_state_cache, state);
103 while (!list_empty(&buffers)) {
104 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
105 printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
106 "refs %d\n", (unsigned long long)eb->start,
107 eb->len, atomic_read(&eb->refs));
108 list_del(&eb->leak_list);
109 kmem_cache_free(extent_buffer_cache, eb);
111 if (extent_state_cache)
112 kmem_cache_destroy(extent_state_cache);
113 if (extent_buffer_cache)
114 kmem_cache_destroy(extent_buffer_cache);
117 void extent_io_tree_init(struct extent_io_tree *tree,
118 struct address_space *mapping)
120 tree->state = RB_ROOT;
121 INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
123 tree->dirty_bytes = 0;
124 spin_lock_init(&tree->lock);
125 spin_lock_init(&tree->buffer_lock);
126 tree->mapping = mapping;
129 static struct extent_state *alloc_extent_state(gfp_t mask)
131 struct extent_state *state;
136 state = kmem_cache_alloc(extent_state_cache, mask);
143 spin_lock_irqsave(&leak_lock, flags);
144 list_add(&state->leak_list, &states);
145 spin_unlock_irqrestore(&leak_lock, flags);
147 atomic_set(&state->refs, 1);
148 init_waitqueue_head(&state->wq);
149 trace_alloc_extent_state(state, mask, _RET_IP_);
153 void free_extent_state(struct extent_state *state)
157 if (atomic_dec_and_test(&state->refs)) {
161 WARN_ON(state->tree);
163 spin_lock_irqsave(&leak_lock, flags);
164 list_del(&state->leak_list);
165 spin_unlock_irqrestore(&leak_lock, flags);
167 trace_free_extent_state(state, _RET_IP_);
168 kmem_cache_free(extent_state_cache, state);
172 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
173 struct rb_node *node)
175 struct rb_node **p = &root->rb_node;
176 struct rb_node *parent = NULL;
177 struct tree_entry *entry;
181 entry = rb_entry(parent, struct tree_entry, rb_node);
183 if (offset < entry->start)
185 else if (offset > entry->end)
191 rb_link_node(node, parent, p);
192 rb_insert_color(node, root);
196 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
197 struct rb_node **prev_ret,
198 struct rb_node **next_ret)
200 struct rb_root *root = &tree->state;
201 struct rb_node *n = root->rb_node;
202 struct rb_node *prev = NULL;
203 struct rb_node *orig_prev = NULL;
204 struct tree_entry *entry;
205 struct tree_entry *prev_entry = NULL;
208 entry = rb_entry(n, struct tree_entry, rb_node);
212 if (offset < entry->start)
214 else if (offset > entry->end)
222 while (prev && offset > prev_entry->end) {
223 prev = rb_next(prev);
224 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
231 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
232 while (prev && offset < prev_entry->start) {
233 prev = rb_prev(prev);
234 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
241 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
244 struct rb_node *prev = NULL;
247 ret = __etree_search(tree, offset, &prev, NULL);
253 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
254 struct extent_state *other)
256 if (tree->ops && tree->ops->merge_extent_hook)
257 tree->ops->merge_extent_hook(tree->mapping->host, new,
262 * utility function to look for merge candidates inside a given range.
263 * Any extents with matching state are merged together into a single
264 * extent in the tree. Extents with EXTENT_IO in their state field
265 * are not merged because the end_io handlers need to be able to do
266 * operations on them without sleeping (or doing allocations/splits).
268 * This should be called with the tree lock held.
270 static void merge_state(struct extent_io_tree *tree,
271 struct extent_state *state)
273 struct extent_state *other;
274 struct rb_node *other_node;
276 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
279 other_node = rb_prev(&state->rb_node);
281 other = rb_entry(other_node, struct extent_state, rb_node);
282 if (other->end == state->start - 1 &&
283 other->state == state->state) {
284 merge_cb(tree, state, other);
285 state->start = other->start;
287 rb_erase(&other->rb_node, &tree->state);
288 free_extent_state(other);
291 other_node = rb_next(&state->rb_node);
293 other = rb_entry(other_node, struct extent_state, rb_node);
294 if (other->start == state->end + 1 &&
295 other->state == state->state) {
296 merge_cb(tree, state, other);
297 state->end = other->end;
299 rb_erase(&other->rb_node, &tree->state);
300 free_extent_state(other);
305 static void set_state_cb(struct extent_io_tree *tree,
306 struct extent_state *state, int *bits)
308 if (tree->ops && tree->ops->set_bit_hook)
309 tree->ops->set_bit_hook(tree->mapping->host, state, bits);
312 static void clear_state_cb(struct extent_io_tree *tree,
313 struct extent_state *state, int *bits)
315 if (tree->ops && tree->ops->clear_bit_hook)
316 tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
319 static void set_state_bits(struct extent_io_tree *tree,
320 struct extent_state *state, int *bits);
323 * insert an extent_state struct into the tree. 'bits' are set on the
324 * struct before it is inserted.
326 * This may return -EEXIST if the extent is already there, in which case the
327 * state struct is freed.
329 * The tree lock is not taken internally. This is a utility function and
330 * probably isn't what you want to call (see set/clear_extent_bit).
332 static int insert_state(struct extent_io_tree *tree,
333 struct extent_state *state, u64 start, u64 end,
336 struct rb_node *node;
339 printk(KERN_ERR "btrfs end < start %llu %llu\n",
340 (unsigned long long)end,
341 (unsigned long long)start);
344 state->start = start;
347 set_state_bits(tree, state, bits);
349 node = tree_insert(&tree->state, end, &state->rb_node);
351 struct extent_state *found;
352 found = rb_entry(node, struct extent_state, rb_node);
353 printk(KERN_ERR "btrfs found node %llu %llu on insert of "
354 "%llu %llu\n", (unsigned long long)found->start,
355 (unsigned long long)found->end,
356 (unsigned long long)start, (unsigned long long)end);
360 merge_state(tree, state);
364 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
367 if (tree->ops && tree->ops->split_extent_hook)
368 tree->ops->split_extent_hook(tree->mapping->host, orig, split);
372 * split a given extent state struct in two, inserting the preallocated
373 * struct 'prealloc' as the newly created second half. 'split' indicates an
374 * offset inside 'orig' where it should be split.
377 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
378 * are two extent state structs in the tree:
379 * prealloc: [orig->start, split - 1]
380 * orig: [ split, orig->end ]
382 * The tree locks are not taken by this function. They need to be held
385 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
386 struct extent_state *prealloc, u64 split)
388 struct rb_node *node;
390 split_cb(tree, orig, split);
392 prealloc->start = orig->start;
393 prealloc->end = split - 1;
394 prealloc->state = orig->state;
397 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
399 free_extent_state(prealloc);
402 prealloc->tree = tree;
406 static struct extent_state *next_state(struct extent_state *state)
408 struct rb_node *next = rb_next(&state->rb_node);
410 return rb_entry(next, struct extent_state, rb_node);
416 * utility function to clear some bits in an extent state struct.
417 * it will optionally wake up any one waiting on this state (wake == 1).
419 * If no bits are set on the state struct after clearing things, the
420 * struct is freed and removed from the tree
422 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
423 struct extent_state *state,
426 struct extent_state *next;
427 int bits_to_clear = *bits & ~EXTENT_CTLBITS;
429 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
430 u64 range = state->end - state->start + 1;
431 WARN_ON(range > tree->dirty_bytes);
432 tree->dirty_bytes -= range;
434 clear_state_cb(tree, state, bits);
435 state->state &= ~bits_to_clear;
438 if (state->state == 0) {
439 next = next_state(state);
441 rb_erase(&state->rb_node, &tree->state);
443 free_extent_state(state);
448 merge_state(tree, state);
449 next = next_state(state);
454 static struct extent_state *
455 alloc_extent_state_atomic(struct extent_state *prealloc)
458 prealloc = alloc_extent_state(GFP_ATOMIC);
463 void extent_io_tree_panic(struct extent_io_tree *tree, int err)
465 btrfs_panic(tree_fs_info(tree), err, "Locking error: "
466 "Extent tree was modified by another "
467 "thread while locked.");
471 * clear some bits on a range in the tree. This may require splitting
472 * or inserting elements in the tree, so the gfp mask is used to
473 * indicate which allocations or sleeping are allowed.
475 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
476 * the given range from the tree regardless of state (ie for truncate).
478 * the range [start, end] is inclusive.
480 * This takes the tree lock, and returns 0 on success and < 0 on error.
482 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
483 int bits, int wake, int delete,
484 struct extent_state **cached_state,
487 struct extent_state *state;
488 struct extent_state *cached;
489 struct extent_state *prealloc = NULL;
490 struct rb_node *node;
496 bits |= ~EXTENT_CTLBITS;
497 bits |= EXTENT_FIRST_DELALLOC;
499 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
502 if (!prealloc && (mask & __GFP_WAIT)) {
503 prealloc = alloc_extent_state(mask);
508 spin_lock(&tree->lock);
510 cached = *cached_state;
513 *cached_state = NULL;
517 if (cached && cached->tree && cached->start <= start &&
518 cached->end > start) {
520 atomic_dec(&cached->refs);
525 free_extent_state(cached);
528 * this search will find the extents that end after
531 node = tree_search(tree, start);
534 state = rb_entry(node, struct extent_state, rb_node);
536 if (state->start > end)
538 WARN_ON(state->end < start);
539 last_end = state->end;
541 /* the state doesn't have the wanted bits, go ahead */
542 if (!(state->state & bits)) {
543 state = next_state(state);
548 * | ---- desired range ---- |
550 * | ------------- state -------------- |
552 * We need to split the extent we found, and may flip
553 * bits on second half.
555 * If the extent we found extends past our range, we
556 * just split and search again. It'll get split again
557 * the next time though.
559 * If the extent we found is inside our range, we clear
560 * the desired bit on it.
563 if (state->start < start) {
564 prealloc = alloc_extent_state_atomic(prealloc);
566 err = split_state(tree, state, prealloc, start);
568 extent_io_tree_panic(tree, err);
573 if (state->end <= end) {
574 state = clear_state_bit(tree, state, &bits, wake);
580 * | ---- desired range ---- |
582 * We need to split the extent, and clear the bit
585 if (state->start <= end && state->end > end) {
586 prealloc = alloc_extent_state_atomic(prealloc);
588 err = split_state(tree, state, prealloc, end + 1);
590 extent_io_tree_panic(tree, err);
595 clear_state_bit(tree, prealloc, &bits, wake);
601 state = clear_state_bit(tree, state, &bits, wake);
603 if (last_end == (u64)-1)
605 start = last_end + 1;
606 if (start <= end && state && !need_resched())
611 spin_unlock(&tree->lock);
613 free_extent_state(prealloc);
620 spin_unlock(&tree->lock);
621 if (mask & __GFP_WAIT)
626 static void wait_on_state(struct extent_io_tree *tree,
627 struct extent_state *state)
628 __releases(tree->lock)
629 __acquires(tree->lock)
632 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
633 spin_unlock(&tree->lock);
635 spin_lock(&tree->lock);
636 finish_wait(&state->wq, &wait);
640 * waits for one or more bits to clear on a range in the state tree.
641 * The range [start, end] is inclusive.
642 * The tree lock is taken by this function
644 void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
646 struct extent_state *state;
647 struct rb_node *node;
649 spin_lock(&tree->lock);
653 * this search will find all the extents that end after
656 node = tree_search(tree, start);
660 state = rb_entry(node, struct extent_state, rb_node);
662 if (state->start > end)
665 if (state->state & bits) {
666 start = state->start;
667 atomic_inc(&state->refs);
668 wait_on_state(tree, state);
669 free_extent_state(state);
672 start = state->end + 1;
677 cond_resched_lock(&tree->lock);
680 spin_unlock(&tree->lock);
683 static void set_state_bits(struct extent_io_tree *tree,
684 struct extent_state *state,
687 int bits_to_set = *bits & ~EXTENT_CTLBITS;
689 set_state_cb(tree, state, bits);
690 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
691 u64 range = state->end - state->start + 1;
692 tree->dirty_bytes += range;
694 state->state |= bits_to_set;
697 static void cache_state(struct extent_state *state,
698 struct extent_state **cached_ptr)
700 if (cached_ptr && !(*cached_ptr)) {
701 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
703 atomic_inc(&state->refs);
708 static void uncache_state(struct extent_state **cached_ptr)
710 if (cached_ptr && (*cached_ptr)) {
711 struct extent_state *state = *cached_ptr;
713 free_extent_state(state);
718 * set some bits on a range in the tree. This may require allocations or
719 * sleeping, so the gfp mask is used to indicate what is allowed.
721 * If any of the exclusive bits are set, this will fail with -EEXIST if some
722 * part of the range already has the desired bits set. The start of the
723 * existing range is returned in failed_start in this case.
725 * [start, end] is inclusive This takes the tree lock.
728 static int __must_check
729 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
730 int bits, int exclusive_bits, u64 *failed_start,
731 struct extent_state **cached_state, gfp_t mask)
733 struct extent_state *state;
734 struct extent_state *prealloc = NULL;
735 struct rb_node *node;
740 bits |= EXTENT_FIRST_DELALLOC;
742 if (!prealloc && (mask & __GFP_WAIT)) {
743 prealloc = alloc_extent_state(mask);
747 spin_lock(&tree->lock);
748 if (cached_state && *cached_state) {
749 state = *cached_state;
750 if (state->start <= start && state->end > start &&
752 node = &state->rb_node;
757 * this search will find all the extents that end after
760 node = tree_search(tree, start);
762 prealloc = alloc_extent_state_atomic(prealloc);
764 err = insert_state(tree, prealloc, start, end, &bits);
766 extent_io_tree_panic(tree, err);
771 state = rb_entry(node, struct extent_state, rb_node);
773 last_start = state->start;
774 last_end = state->end;
777 * | ---- desired range ---- |
780 * Just lock what we found and keep going
782 if (state->start == start && state->end <= end) {
783 if (state->state & exclusive_bits) {
784 *failed_start = state->start;
789 set_state_bits(tree, state, &bits);
790 cache_state(state, cached_state);
791 merge_state(tree, state);
792 if (last_end == (u64)-1)
794 start = last_end + 1;
795 state = next_state(state);
796 if (start < end && state && state->start == start &&
803 * | ---- desired range ---- |
806 * | ------------- state -------------- |
808 * We need to split the extent we found, and may flip bits on
811 * If the extent we found extends past our
812 * range, we just split and search again. It'll get split
813 * again the next time though.
815 * If the extent we found is inside our range, we set the
818 if (state->start < start) {
819 if (state->state & exclusive_bits) {
820 *failed_start = start;
825 prealloc = alloc_extent_state_atomic(prealloc);
827 err = split_state(tree, state, prealloc, start);
829 extent_io_tree_panic(tree, err);
834 if (state->end <= end) {
835 set_state_bits(tree, state, &bits);
836 cache_state(state, cached_state);
837 merge_state(tree, state);
838 if (last_end == (u64)-1)
840 start = last_end + 1;
841 state = next_state(state);
842 if (start < end && state && state->start == start &&
849 * | ---- desired range ---- |
850 * | state | or | state |
852 * There's a hole, we need to insert something in it and
853 * ignore the extent we found.
855 if (state->start > start) {
857 if (end < last_start)
860 this_end = last_start - 1;
862 prealloc = alloc_extent_state_atomic(prealloc);
866 * Avoid to free 'prealloc' if it can be merged with
869 err = insert_state(tree, prealloc, start, this_end,
872 extent_io_tree_panic(tree, err);
874 cache_state(prealloc, cached_state);
876 start = this_end + 1;
880 * | ---- desired range ---- |
882 * We need to split the extent, and set the bit
885 if (state->start <= end && state->end > end) {
886 if (state->state & exclusive_bits) {
887 *failed_start = start;
892 prealloc = alloc_extent_state_atomic(prealloc);
894 err = split_state(tree, state, prealloc, end + 1);
896 extent_io_tree_panic(tree, err);
898 set_state_bits(tree, prealloc, &bits);
899 cache_state(prealloc, cached_state);
900 merge_state(tree, prealloc);
908 spin_unlock(&tree->lock);
910 free_extent_state(prealloc);
917 spin_unlock(&tree->lock);
918 if (mask & __GFP_WAIT)
923 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits,
924 u64 *failed_start, struct extent_state **cached_state,
927 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
933 * convert_extent_bit - convert all bits in a given range from one bit to
935 * @tree: the io tree to search
936 * @start: the start offset in bytes
937 * @end: the end offset in bytes (inclusive)
938 * @bits: the bits to set in this range
939 * @clear_bits: the bits to clear in this range
940 * @cached_state: state that we're going to cache
941 * @mask: the allocation mask
943 * This will go through and set bits for the given range. If any states exist
944 * already in this range they are set with the given bit and cleared of the
945 * clear_bits. This is only meant to be used by things that are mergeable, ie
946 * converting from say DELALLOC to DIRTY. This is not meant to be used with
947 * boundary bits like LOCK.
949 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
950 int bits, int clear_bits,
951 struct extent_state **cached_state, gfp_t mask)
953 struct extent_state *state;
954 struct extent_state *prealloc = NULL;
955 struct rb_node *node;
961 if (!prealloc && (mask & __GFP_WAIT)) {
962 prealloc = alloc_extent_state(mask);
967 spin_lock(&tree->lock);
968 if (cached_state && *cached_state) {
969 state = *cached_state;
970 if (state->start <= start && state->end > start &&
972 node = &state->rb_node;
978 * this search will find all the extents that end after
981 node = tree_search(tree, start);
983 prealloc = alloc_extent_state_atomic(prealloc);
988 err = insert_state(tree, prealloc, start, end, &bits);
991 extent_io_tree_panic(tree, err);
994 state = rb_entry(node, struct extent_state, rb_node);
996 last_start = state->start;
997 last_end = state->end;
1000 * | ---- desired range ---- |
1003 * Just lock what we found and keep going
1005 if (state->start == start && state->end <= end) {
1006 set_state_bits(tree, state, &bits);
1007 cache_state(state, cached_state);
1008 state = clear_state_bit(tree, state, &clear_bits, 0);
1009 if (last_end == (u64)-1)
1011 start = last_end + 1;
1012 if (start < end && state && state->start == start &&
1019 * | ---- desired range ---- |
1022 * | ------------- state -------------- |
1024 * We need to split the extent we found, and may flip bits on
1027 * If the extent we found extends past our
1028 * range, we just split and search again. It'll get split
1029 * again the next time though.
1031 * If the extent we found is inside our range, we set the
1032 * desired bit on it.
1034 if (state->start < start) {
1035 prealloc = alloc_extent_state_atomic(prealloc);
1040 err = split_state(tree, state, prealloc, start);
1042 extent_io_tree_panic(tree, err);
1046 if (state->end <= end) {
1047 set_state_bits(tree, state, &bits);
1048 cache_state(state, cached_state);
1049 state = clear_state_bit(tree, state, &clear_bits, 0);
1050 if (last_end == (u64)-1)
1052 start = last_end + 1;
1053 if (start < end && state && state->start == start &&
1060 * | ---- desired range ---- |
1061 * | state | or | state |
1063 * There's a hole, we need to insert something in it and
1064 * ignore the extent we found.
1066 if (state->start > start) {
1068 if (end < last_start)
1071 this_end = last_start - 1;
1073 prealloc = alloc_extent_state_atomic(prealloc);
1080 * Avoid to free 'prealloc' if it can be merged with
1083 err = insert_state(tree, prealloc, start, this_end,
1086 extent_io_tree_panic(tree, err);
1087 cache_state(prealloc, cached_state);
1089 start = this_end + 1;
1093 * | ---- desired range ---- |
1095 * We need to split the extent, and set the bit
1098 if (state->start <= end && state->end > end) {
1099 prealloc = alloc_extent_state_atomic(prealloc);
1105 err = split_state(tree, state, prealloc, end + 1);
1107 extent_io_tree_panic(tree, err);
1109 set_state_bits(tree, prealloc, &bits);
1110 cache_state(prealloc, cached_state);
1111 clear_state_bit(tree, prealloc, &clear_bits, 0);
1119 spin_unlock(&tree->lock);
1121 free_extent_state(prealloc);
1128 spin_unlock(&tree->lock);
1129 if (mask & __GFP_WAIT)
1134 /* wrappers around set/clear extent bit */
1135 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1138 return set_extent_bit(tree, start, end, EXTENT_DIRTY, NULL,
1142 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1143 int bits, gfp_t mask)
1145 return set_extent_bit(tree, start, end, bits, NULL,
1149 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1150 int bits, gfp_t mask)
1152 return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
1155 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
1156 struct extent_state **cached_state, gfp_t mask)
1158 return set_extent_bit(tree, start, end,
1159 EXTENT_DELALLOC | EXTENT_UPTODATE,
1160 NULL, cached_state, mask);
1163 int set_extent_defrag(struct extent_io_tree *tree, u64 start, u64 end,
1164 struct extent_state **cached_state, gfp_t mask)
1166 return set_extent_bit(tree, start, end,
1167 EXTENT_DELALLOC | EXTENT_UPTODATE | EXTENT_DEFRAG,
1168 NULL, cached_state, mask);
1171 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1174 return clear_extent_bit(tree, start, end,
1175 EXTENT_DIRTY | EXTENT_DELALLOC |
1176 EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
1179 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
1182 return set_extent_bit(tree, start, end, EXTENT_NEW, NULL,
1186 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
1187 struct extent_state **cached_state, gfp_t mask)
1189 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0,
1190 cached_state, mask);
1193 int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
1194 struct extent_state **cached_state, gfp_t mask)
1196 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
1197 cached_state, mask);
1201 * either insert or lock state struct between start and end use mask to tell
1202 * us if waiting is desired.
1204 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1205 int bits, struct extent_state **cached_state)
1210 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
1211 EXTENT_LOCKED, &failed_start,
1212 cached_state, GFP_NOFS);
1213 if (err == -EEXIST) {
1214 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1215 start = failed_start;
1218 WARN_ON(start > end);
1223 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1225 return lock_extent_bits(tree, start, end, 0, NULL);
1228 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1233 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1234 &failed_start, NULL, GFP_NOFS);
1235 if (err == -EEXIST) {
1236 if (failed_start > start)
1237 clear_extent_bit(tree, start, failed_start - 1,
1238 EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS);
1244 int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
1245 struct extent_state **cached, gfp_t mask)
1247 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
1251 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1253 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
1258 * helper function to set both pages and extents in the tree writeback
1260 static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1262 unsigned long index = start >> PAGE_CACHE_SHIFT;
1263 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1266 while (index <= end_index) {
1267 page = find_get_page(tree->mapping, index);
1268 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1269 set_page_writeback(page);
1270 page_cache_release(page);
1276 /* find the first state struct with 'bits' set after 'start', and
1277 * return it. tree->lock must be held. NULL will returned if
1278 * nothing was found after 'start'
1280 struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
1281 u64 start, int bits)
1283 struct rb_node *node;
1284 struct extent_state *state;
1287 * this search will find all the extents that end after
1290 node = tree_search(tree, start);
1295 state = rb_entry(node, struct extent_state, rb_node);
1296 if (state->end >= start && (state->state & bits))
1299 node = rb_next(node);
1308 * find the first offset in the io tree with 'bits' set. zero is
1309 * returned if we find something, and *start_ret and *end_ret are
1310 * set to reflect the state struct that was found.
1312 * If nothing was found, 1 is returned. If found something, return 0.
1314 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1315 u64 *start_ret, u64 *end_ret, int bits,
1316 struct extent_state **cached_state)
1318 struct extent_state *state;
1322 spin_lock(&tree->lock);
1323 if (cached_state && *cached_state) {
1324 state = *cached_state;
1325 if (state->end == start - 1 && state->tree) {
1326 n = rb_next(&state->rb_node);
1328 state = rb_entry(n, struct extent_state,
1330 if (state->state & bits)
1334 free_extent_state(*cached_state);
1335 *cached_state = NULL;
1338 free_extent_state(*cached_state);
1339 *cached_state = NULL;
1342 state = find_first_extent_bit_state(tree, start, bits);
1345 cache_state(state, cached_state);
1346 *start_ret = state->start;
1347 *end_ret = state->end;
1351 spin_unlock(&tree->lock);
1356 * find a contiguous range of bytes in the file marked as delalloc, not
1357 * more than 'max_bytes'. start and end are used to return the range,
1359 * 1 is returned if we find something, 0 if nothing was in the tree
1361 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1362 u64 *start, u64 *end, u64 max_bytes,
1363 struct extent_state **cached_state)
1365 struct rb_node *node;
1366 struct extent_state *state;
1367 u64 cur_start = *start;
1369 u64 total_bytes = 0;
1371 spin_lock(&tree->lock);
1374 * this search will find all the extents that end after
1377 node = tree_search(tree, cur_start);
1385 state = rb_entry(node, struct extent_state, rb_node);
1386 if (found && (state->start != cur_start ||
1387 (state->state & EXTENT_BOUNDARY))) {
1390 if (!(state->state & EXTENT_DELALLOC)) {
1396 *start = state->start;
1397 *cached_state = state;
1398 atomic_inc(&state->refs);
1402 cur_start = state->end + 1;
1403 node = rb_next(node);
1406 total_bytes += state->end - state->start + 1;
1407 if (total_bytes >= max_bytes)
1411 spin_unlock(&tree->lock);
1415 static noinline void __unlock_for_delalloc(struct inode *inode,
1416 struct page *locked_page,
1420 struct page *pages[16];
1421 unsigned long index = start >> PAGE_CACHE_SHIFT;
1422 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1423 unsigned long nr_pages = end_index - index + 1;
1426 if (index == locked_page->index && end_index == index)
1429 while (nr_pages > 0) {
1430 ret = find_get_pages_contig(inode->i_mapping, index,
1431 min_t(unsigned long, nr_pages,
1432 ARRAY_SIZE(pages)), pages);
1433 for (i = 0; i < ret; i++) {
1434 if (pages[i] != locked_page)
1435 unlock_page(pages[i]);
1436 page_cache_release(pages[i]);
1444 static noinline int lock_delalloc_pages(struct inode *inode,
1445 struct page *locked_page,
1449 unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
1450 unsigned long start_index = index;
1451 unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
1452 unsigned long pages_locked = 0;
1453 struct page *pages[16];
1454 unsigned long nrpages;
1458 /* the caller is responsible for locking the start index */
1459 if (index == locked_page->index && index == end_index)
1462 /* skip the page at the start index */
1463 nrpages = end_index - index + 1;
1464 while (nrpages > 0) {
1465 ret = find_get_pages_contig(inode->i_mapping, index,
1466 min_t(unsigned long,
1467 nrpages, ARRAY_SIZE(pages)), pages);
1472 /* now we have an array of pages, lock them all */
1473 for (i = 0; i < ret; i++) {
1475 * the caller is taking responsibility for
1478 if (pages[i] != locked_page) {
1479 lock_page(pages[i]);
1480 if (!PageDirty(pages[i]) ||
1481 pages[i]->mapping != inode->i_mapping) {
1483 unlock_page(pages[i]);
1484 page_cache_release(pages[i]);
1488 page_cache_release(pages[i]);
1497 if (ret && pages_locked) {
1498 __unlock_for_delalloc(inode, locked_page,
1500 ((u64)(start_index + pages_locked - 1)) <<
1507 * find a contiguous range of bytes in the file marked as delalloc, not
1508 * more than 'max_bytes'. start and end are used to return the range,
1510 * 1 is returned if we find something, 0 if nothing was in the tree
1512 static noinline u64 find_lock_delalloc_range(struct inode *inode,
1513 struct extent_io_tree *tree,
1514 struct page *locked_page,
1515 u64 *start, u64 *end,
1521 struct extent_state *cached_state = NULL;
1526 /* step one, find a bunch of delalloc bytes starting at start */
1527 delalloc_start = *start;
1529 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1530 max_bytes, &cached_state);
1531 if (!found || delalloc_end <= *start) {
1532 *start = delalloc_start;
1533 *end = delalloc_end;
1534 free_extent_state(cached_state);
1539 * start comes from the offset of locked_page. We have to lock
1540 * pages in order, so we can't process delalloc bytes before
1543 if (delalloc_start < *start)
1544 delalloc_start = *start;
1547 * make sure to limit the number of pages we try to lock down
1550 if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1551 delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
1553 /* step two, lock all the pages after the page that has start */
1554 ret = lock_delalloc_pages(inode, locked_page,
1555 delalloc_start, delalloc_end);
1556 if (ret == -EAGAIN) {
1557 /* some of the pages are gone, lets avoid looping by
1558 * shortening the size of the delalloc range we're searching
1560 free_extent_state(cached_state);
1562 unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
1563 max_bytes = PAGE_CACHE_SIZE - offset;
1571 BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
1573 /* step three, lock the state bits for the whole range */
1574 lock_extent_bits(tree, delalloc_start, delalloc_end, 0, &cached_state);
1576 /* then test to make sure it is all still delalloc */
1577 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1578 EXTENT_DELALLOC, 1, cached_state);
1580 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1581 &cached_state, GFP_NOFS);
1582 __unlock_for_delalloc(inode, locked_page,
1583 delalloc_start, delalloc_end);
1587 free_extent_state(cached_state);
1588 *start = delalloc_start;
1589 *end = delalloc_end;
1594 int extent_clear_unlock_delalloc(struct inode *inode,
1595 struct extent_io_tree *tree,
1596 u64 start, u64 end, struct page *locked_page,
1600 struct page *pages[16];
1601 unsigned long index = start >> PAGE_CACHE_SHIFT;
1602 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1603 unsigned long nr_pages = end_index - index + 1;
1607 if (op & EXTENT_CLEAR_UNLOCK)
1608 clear_bits |= EXTENT_LOCKED;
1609 if (op & EXTENT_CLEAR_DIRTY)
1610 clear_bits |= EXTENT_DIRTY;
1612 if (op & EXTENT_CLEAR_DELALLOC)
1613 clear_bits |= EXTENT_DELALLOC;
1615 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1616 if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
1617 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
1618 EXTENT_SET_PRIVATE2)))
1621 while (nr_pages > 0) {
1622 ret = find_get_pages_contig(inode->i_mapping, index,
1623 min_t(unsigned long,
1624 nr_pages, ARRAY_SIZE(pages)), pages);
1625 for (i = 0; i < ret; i++) {
1627 if (op & EXTENT_SET_PRIVATE2)
1628 SetPagePrivate2(pages[i]);
1630 if (pages[i] == locked_page) {
1631 page_cache_release(pages[i]);
1634 if (op & EXTENT_CLEAR_DIRTY)
1635 clear_page_dirty_for_io(pages[i]);
1636 if (op & EXTENT_SET_WRITEBACK)
1637 set_page_writeback(pages[i]);
1638 if (op & EXTENT_END_WRITEBACK)
1639 end_page_writeback(pages[i]);
1640 if (op & EXTENT_CLEAR_UNLOCK_PAGE)
1641 unlock_page(pages[i]);
1642 page_cache_release(pages[i]);
1652 * count the number of bytes in the tree that have a given bit(s)
1653 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1654 * cached. The total number found is returned.
1656 u64 count_range_bits(struct extent_io_tree *tree,
1657 u64 *start, u64 search_end, u64 max_bytes,
1658 unsigned long bits, int contig)
1660 struct rb_node *node;
1661 struct extent_state *state;
1662 u64 cur_start = *start;
1663 u64 total_bytes = 0;
1667 if (search_end <= cur_start) {
1672 spin_lock(&tree->lock);
1673 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1674 total_bytes = tree->dirty_bytes;
1678 * this search will find all the extents that end after
1681 node = tree_search(tree, cur_start);
1686 state = rb_entry(node, struct extent_state, rb_node);
1687 if (state->start > search_end)
1689 if (contig && found && state->start > last + 1)
1691 if (state->end >= cur_start && (state->state & bits) == bits) {
1692 total_bytes += min(search_end, state->end) + 1 -
1693 max(cur_start, state->start);
1694 if (total_bytes >= max_bytes)
1697 *start = max(cur_start, state->start);
1701 } else if (contig && found) {
1704 node = rb_next(node);
1709 spin_unlock(&tree->lock);
1714 * set the private field for a given byte offset in the tree. If there isn't
1715 * an extent_state there already, this does nothing.
1717 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1719 struct rb_node *node;
1720 struct extent_state *state;
1723 spin_lock(&tree->lock);
1725 * this search will find all the extents that end after
1728 node = tree_search(tree, start);
1733 state = rb_entry(node, struct extent_state, rb_node);
1734 if (state->start != start) {
1738 state->private = private;
1740 spin_unlock(&tree->lock);
1744 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1746 struct rb_node *node;
1747 struct extent_state *state;
1750 spin_lock(&tree->lock);
1752 * this search will find all the extents that end after
1755 node = tree_search(tree, start);
1760 state = rb_entry(node, struct extent_state, rb_node);
1761 if (state->start != start) {
1765 *private = state->private;
1767 spin_unlock(&tree->lock);
1772 * searches a range in the state tree for a given mask.
1773 * If 'filled' == 1, this returns 1 only if every extent in the tree
1774 * has the bits set. Otherwise, 1 is returned if any bit in the
1775 * range is found set.
1777 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1778 int bits, int filled, struct extent_state *cached)
1780 struct extent_state *state = NULL;
1781 struct rb_node *node;
1784 spin_lock(&tree->lock);
1785 if (cached && cached->tree && cached->start <= start &&
1786 cached->end > start)
1787 node = &cached->rb_node;
1789 node = tree_search(tree, start);
1790 while (node && start <= end) {
1791 state = rb_entry(node, struct extent_state, rb_node);
1793 if (filled && state->start > start) {
1798 if (state->start > end)
1801 if (state->state & bits) {
1805 } else if (filled) {
1810 if (state->end == (u64)-1)
1813 start = state->end + 1;
1816 node = rb_next(node);
1823 spin_unlock(&tree->lock);
1828 * helper function to set a given page up to date if all the
1829 * extents in the tree for that page are up to date
1831 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
1833 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1834 u64 end = start + PAGE_CACHE_SIZE - 1;
1835 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1836 SetPageUptodate(page);
1840 * helper function to unlock a page if all the extents in the tree
1841 * for that page are unlocked
1843 static void check_page_locked(struct extent_io_tree *tree, struct page *page)
1845 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1846 u64 end = start + PAGE_CACHE_SIZE - 1;
1847 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
1852 * helper function to end page writeback if all the extents
1853 * in the tree for that page are done with writeback
1855 static void check_page_writeback(struct extent_io_tree *tree,
1858 end_page_writeback(page);
1862 * When IO fails, either with EIO or csum verification fails, we
1863 * try other mirrors that might have a good copy of the data. This
1864 * io_failure_record is used to record state as we go through all the
1865 * mirrors. If another mirror has good data, the page is set up to date
1866 * and things continue. If a good mirror can't be found, the original
1867 * bio end_io callback is called to indicate things have failed.
1869 struct io_failure_record {
1874 unsigned long bio_flags;
1880 static int free_io_failure(struct inode *inode, struct io_failure_record *rec,
1885 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1887 set_state_private(failure_tree, rec->start, 0);
1888 ret = clear_extent_bits(failure_tree, rec->start,
1889 rec->start + rec->len - 1,
1890 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
1895 ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
1896 rec->start + rec->len - 1,
1897 EXTENT_DAMAGED, GFP_NOFS);
1906 static void repair_io_failure_callback(struct bio *bio, int err)
1908 complete(bio->bi_private);
1912 * this bypasses the standard btrfs submit functions deliberately, as
1913 * the standard behavior is to write all copies in a raid setup. here we only
1914 * want to write the one bad copy. so we do the mapping for ourselves and issue
1915 * submit_bio directly.
1916 * to avoid any synchonization issues, wait for the data after writing, which
1917 * actually prevents the read that triggered the error from finishing.
1918 * currently, there can be no more than two copies of every data bit. thus,
1919 * exactly one rewrite is required.
1921 int repair_io_failure(struct btrfs_mapping_tree *map_tree, u64 start,
1922 u64 length, u64 logical, struct page *page,
1926 struct btrfs_device *dev;
1927 DECLARE_COMPLETION_ONSTACK(compl);
1930 struct btrfs_bio *bbio = NULL;
1933 BUG_ON(!mirror_num);
1935 bio = bio_alloc(GFP_NOFS, 1);
1938 bio->bi_private = &compl;
1939 bio->bi_end_io = repair_io_failure_callback;
1941 map_length = length;
1943 ret = btrfs_map_block(map_tree, WRITE, logical,
1944 &map_length, &bbio, mirror_num);
1949 BUG_ON(mirror_num != bbio->mirror_num);
1950 sector = bbio->stripes[mirror_num-1].physical >> 9;
1951 bio->bi_sector = sector;
1952 dev = bbio->stripes[mirror_num-1].dev;
1954 if (!dev || !dev->bdev || !dev->writeable) {
1958 bio->bi_bdev = dev->bdev;
1959 bio_add_page(bio, page, length, start-page_offset(page));
1960 btrfsic_submit_bio(WRITE_SYNC, bio);
1961 wait_for_completion(&compl);
1963 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
1964 /* try to remap that extent elsewhere? */
1966 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
1970 printk_ratelimited_in_rcu(KERN_INFO "btrfs read error corrected: ino %lu off %llu "
1971 "(dev %s sector %llu)\n", page->mapping->host->i_ino,
1972 start, rcu_str_deref(dev->name), sector);
1978 int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb,
1981 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
1982 u64 start = eb->start;
1983 unsigned long i, num_pages = num_extent_pages(eb->start, eb->len);
1986 for (i = 0; i < num_pages; i++) {
1987 struct page *p = extent_buffer_page(eb, i);
1988 ret = repair_io_failure(map_tree, start, PAGE_CACHE_SIZE,
1989 start, p, mirror_num);
1992 start += PAGE_CACHE_SIZE;
1999 * each time an IO finishes, we do a fast check in the IO failure tree
2000 * to see if we need to process or clean up an io_failure_record
2002 static int clean_io_failure(u64 start, struct page *page)
2005 u64 private_failure;
2006 struct io_failure_record *failrec;
2007 struct btrfs_mapping_tree *map_tree;
2008 struct extent_state *state;
2012 struct inode *inode = page->mapping->host;
2015 ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
2016 (u64)-1, 1, EXTENT_DIRTY, 0);
2020 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree, start,
2025 failrec = (struct io_failure_record *)(unsigned long) private_failure;
2026 BUG_ON(!failrec->this_mirror);
2028 if (failrec->in_validation) {
2029 /* there was no real error, just free the record */
2030 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2036 spin_lock(&BTRFS_I(inode)->io_tree.lock);
2037 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
2040 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
2042 if (state && state->start == failrec->start) {
2043 map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree;
2044 num_copies = btrfs_num_copies(map_tree, failrec->logical,
2046 if (num_copies > 1) {
2047 ret = repair_io_failure(map_tree, start, failrec->len,
2048 failrec->logical, page,
2049 failrec->failed_mirror);
2056 ret = free_io_failure(inode, failrec, did_repair);
2062 * this is a generic handler for readpage errors (default
2063 * readpage_io_failed_hook). if other copies exist, read those and write back
2064 * good data to the failed position. does not investigate in remapping the
2065 * failed extent elsewhere, hoping the device will be smart enough to do this as
2069 static int bio_readpage_error(struct bio *failed_bio, struct page *page,
2070 u64 start, u64 end, int failed_mirror,
2071 struct extent_state *state)
2073 struct io_failure_record *failrec = NULL;
2075 struct extent_map *em;
2076 struct inode *inode = page->mapping->host;
2077 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2078 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2079 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2086 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
2088 ret = get_state_private(failure_tree, start, &private);
2090 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2093 failrec->start = start;
2094 failrec->len = end - start + 1;
2095 failrec->this_mirror = 0;
2096 failrec->bio_flags = 0;
2097 failrec->in_validation = 0;
2099 read_lock(&em_tree->lock);
2100 em = lookup_extent_mapping(em_tree, start, failrec->len);
2102 read_unlock(&em_tree->lock);
2107 if (em->start > start || em->start + em->len < start) {
2108 free_extent_map(em);
2111 read_unlock(&em_tree->lock);
2113 if (!em || IS_ERR(em)) {
2117 logical = start - em->start;
2118 logical = em->block_start + logical;
2119 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2120 logical = em->block_start;
2121 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2122 extent_set_compress_type(&failrec->bio_flags,
2125 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2126 "len=%llu\n", logical, start, failrec->len);
2127 failrec->logical = logical;
2128 free_extent_map(em);
2130 /* set the bits in the private failure tree */
2131 ret = set_extent_bits(failure_tree, start, end,
2132 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
2134 ret = set_state_private(failure_tree, start,
2135 (u64)(unsigned long)failrec);
2136 /* set the bits in the inode's tree */
2138 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED,
2145 failrec = (struct io_failure_record *)(unsigned long)private;
2146 pr_debug("bio_readpage_error: (found) logical=%llu, "
2147 "start=%llu, len=%llu, validation=%d\n",
2148 failrec->logical, failrec->start, failrec->len,
2149 failrec->in_validation);
2151 * when data can be on disk more than twice, add to failrec here
2152 * (e.g. with a list for failed_mirror) to make
2153 * clean_io_failure() clean all those errors at once.
2156 num_copies = btrfs_num_copies(
2157 &BTRFS_I(inode)->root->fs_info->mapping_tree,
2158 failrec->logical, failrec->len);
2159 if (num_copies == 1) {
2161 * we only have a single copy of the data, so don't bother with
2162 * all the retry and error correction code that follows. no
2163 * matter what the error is, it is very likely to persist.
2165 pr_debug("bio_readpage_error: cannot repair, num_copies == 1. "
2166 "state=%p, num_copies=%d, next_mirror %d, "
2167 "failed_mirror %d\n", state, num_copies,
2168 failrec->this_mirror, failed_mirror);
2169 free_io_failure(inode, failrec, 0);
2174 spin_lock(&tree->lock);
2175 state = find_first_extent_bit_state(tree, failrec->start,
2177 if (state && state->start != failrec->start)
2179 spin_unlock(&tree->lock);
2183 * there are two premises:
2184 * a) deliver good data to the caller
2185 * b) correct the bad sectors on disk
2187 if (failed_bio->bi_vcnt > 1) {
2189 * to fulfill b), we need to know the exact failing sectors, as
2190 * we don't want to rewrite any more than the failed ones. thus,
2191 * we need separate read requests for the failed bio
2193 * if the following BUG_ON triggers, our validation request got
2194 * merged. we need separate requests for our algorithm to work.
2196 BUG_ON(failrec->in_validation);
2197 failrec->in_validation = 1;
2198 failrec->this_mirror = failed_mirror;
2199 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
2202 * we're ready to fulfill a) and b) alongside. get a good copy
2203 * of the failed sector and if we succeed, we have setup
2204 * everything for repair_io_failure to do the rest for us.
2206 if (failrec->in_validation) {
2207 BUG_ON(failrec->this_mirror != failed_mirror);
2208 failrec->in_validation = 0;
2209 failrec->this_mirror = 0;
2211 failrec->failed_mirror = failed_mirror;
2212 failrec->this_mirror++;
2213 if (failrec->this_mirror == failed_mirror)
2214 failrec->this_mirror++;
2215 read_mode = READ_SYNC;
2218 if (!state || failrec->this_mirror > num_copies) {
2219 pr_debug("bio_readpage_error: (fail) state=%p, num_copies=%d, "
2220 "next_mirror %d, failed_mirror %d\n", state,
2221 num_copies, failrec->this_mirror, failed_mirror);
2222 free_io_failure(inode, failrec, 0);
2226 bio = bio_alloc(GFP_NOFS, 1);
2228 free_io_failure(inode, failrec, 0);
2231 bio->bi_private = state;
2232 bio->bi_end_io = failed_bio->bi_end_io;
2233 bio->bi_sector = failrec->logical >> 9;
2234 bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
2237 bio_add_page(bio, page, failrec->len, start - page_offset(page));
2239 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2240 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode,
2241 failrec->this_mirror, num_copies, failrec->in_validation);
2243 ret = tree->ops->submit_bio_hook(inode, read_mode, bio,
2244 failrec->this_mirror,
2245 failrec->bio_flags, 0);
2249 /* lots and lots of room for performance fixes in the end_bio funcs */
2251 int end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2253 int uptodate = (err == 0);
2254 struct extent_io_tree *tree;
2257 tree = &BTRFS_I(page->mapping->host)->io_tree;
2259 if (tree->ops && tree->ops->writepage_end_io_hook) {
2260 ret = tree->ops->writepage_end_io_hook(page, start,
2261 end, NULL, uptodate);
2267 ClearPageUptodate(page);
2274 * after a writepage IO is done, we need to:
2275 * clear the uptodate bits on error
2276 * clear the writeback bits in the extent tree for this IO
2277 * end_page_writeback if the page has no more pending IO
2279 * Scheduling is not allowed, so the extent state tree is expected
2280 * to have one and only one object corresponding to this IO.
2282 static void end_bio_extent_writepage(struct bio *bio, int err)
2284 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2285 struct extent_io_tree *tree;
2291 struct page *page = bvec->bv_page;
2292 tree = &BTRFS_I(page->mapping->host)->io_tree;
2294 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
2296 end = start + bvec->bv_len - 1;
2298 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
2303 if (--bvec >= bio->bi_io_vec)
2304 prefetchw(&bvec->bv_page->flags);
2306 if (end_extent_writepage(page, err, start, end))
2310 end_page_writeback(page);
2312 check_page_writeback(tree, page);
2313 } while (bvec >= bio->bi_io_vec);
2319 * after a readpage IO is done, we need to:
2320 * clear the uptodate bits on error
2321 * set the uptodate bits if things worked
2322 * set the page up to date if all extents in the tree are uptodate
2323 * clear the lock bit in the extent tree
2324 * unlock the page if there are no other extents locked for it
2326 * Scheduling is not allowed, so the extent state tree is expected
2327 * to have one and only one object corresponding to this IO.
2329 static void end_bio_extent_readpage(struct bio *bio, int err)
2331 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
2332 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
2333 struct bio_vec *bvec = bio->bi_io_vec;
2334 struct extent_io_tree *tree;
2345 struct page *page = bvec->bv_page;
2346 struct extent_state *cached = NULL;
2347 struct extent_state *state;
2349 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2350 "mirror=%ld\n", (u64)bio->bi_sector, err,
2351 (long int)bio->bi_bdev);
2352 tree = &BTRFS_I(page->mapping->host)->io_tree;
2354 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
2356 end = start + bvec->bv_len - 1;
2358 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
2363 if (++bvec <= bvec_end)
2364 prefetchw(&bvec->bv_page->flags);
2366 spin_lock(&tree->lock);
2367 state = find_first_extent_bit_state(tree, start, EXTENT_LOCKED);
2368 if (state && state->start == start) {
2370 * take a reference on the state, unlock will drop
2373 cache_state(state, &cached);
2375 spin_unlock(&tree->lock);
2377 mirror = (int)(unsigned long)bio->bi_bdev;
2378 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
2379 ret = tree->ops->readpage_end_io_hook(page, start, end,
2384 clean_io_failure(start, page);
2387 if (!uptodate && tree->ops && tree->ops->readpage_io_failed_hook) {
2388 ret = tree->ops->readpage_io_failed_hook(page, mirror);
2390 test_bit(BIO_UPTODATE, &bio->bi_flags))
2392 } else if (!uptodate) {
2394 * The generic bio_readpage_error handles errors the
2395 * following way: If possible, new read requests are
2396 * created and submitted and will end up in
2397 * end_bio_extent_readpage as well (if we're lucky, not
2398 * in the !uptodate case). In that case it returns 0 and
2399 * we just go on with the next page in our bio. If it
2400 * can't handle the error it will return -EIO and we
2401 * remain responsible for that page.
2403 ret = bio_readpage_error(bio, page, start, end, mirror, NULL);
2406 test_bit(BIO_UPTODATE, &bio->bi_flags);
2409 uncache_state(&cached);
2414 if (uptodate && tree->track_uptodate) {
2415 set_extent_uptodate(tree, start, end, &cached,
2418 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2422 SetPageUptodate(page);
2424 ClearPageUptodate(page);
2430 check_page_uptodate(tree, page);
2432 ClearPageUptodate(page);
2435 check_page_locked(tree, page);
2437 } while (bvec <= bvec_end);
2443 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2448 bio = bio_alloc(gfp_flags, nr_vecs);
2450 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2451 while (!bio && (nr_vecs /= 2))
2452 bio = bio_alloc(gfp_flags, nr_vecs);
2457 bio->bi_bdev = bdev;
2458 bio->bi_sector = first_sector;
2464 * Since writes are async, they will only return -ENOMEM.
2465 * Reads can return the full range of I/O error conditions.
2467 static int __must_check submit_one_bio(int rw, struct bio *bio,
2468 int mirror_num, unsigned long bio_flags)
2471 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2472 struct page *page = bvec->bv_page;
2473 struct extent_io_tree *tree = bio->bi_private;
2476 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
2478 bio->bi_private = NULL;
2482 if (tree->ops && tree->ops->submit_bio_hook)
2483 ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
2484 mirror_num, bio_flags, start);
2486 btrfsic_submit_bio(rw, bio);
2488 if (bio_flagged(bio, BIO_EOPNOTSUPP))
2494 static int merge_bio(struct extent_io_tree *tree, struct page *page,
2495 unsigned long offset, size_t size, struct bio *bio,
2496 unsigned long bio_flags)
2499 if (tree->ops && tree->ops->merge_bio_hook)
2500 ret = tree->ops->merge_bio_hook(page, offset, size, bio,
2507 static int submit_extent_page(int rw, struct extent_io_tree *tree,
2508 struct page *page, sector_t sector,
2509 size_t size, unsigned long offset,
2510 struct block_device *bdev,
2511 struct bio **bio_ret,
2512 unsigned long max_pages,
2513 bio_end_io_t end_io_func,
2515 unsigned long prev_bio_flags,
2516 unsigned long bio_flags)
2522 int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
2523 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2524 size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
2526 if (bio_ret && *bio_ret) {
2529 contig = bio->bi_sector == sector;
2531 contig = bio->bi_sector + (bio->bi_size >> 9) ==
2534 if (prev_bio_flags != bio_flags || !contig ||
2535 merge_bio(tree, page, offset, page_size, bio, bio_flags) ||
2536 bio_add_page(bio, page, page_size, offset) < page_size) {
2537 ret = submit_one_bio(rw, bio, mirror_num,
2546 if (this_compressed)
2549 nr = bio_get_nr_vecs(bdev);
2551 bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
2555 bio_add_page(bio, page, page_size, offset);
2556 bio->bi_end_io = end_io_func;
2557 bio->bi_private = tree;
2562 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
2567 void attach_extent_buffer_page(struct extent_buffer *eb, struct page *page)
2569 if (!PagePrivate(page)) {
2570 SetPagePrivate(page);
2571 page_cache_get(page);
2572 set_page_private(page, (unsigned long)eb);
2574 WARN_ON(page->private != (unsigned long)eb);
2578 void set_page_extent_mapped(struct page *page)
2580 if (!PagePrivate(page)) {
2581 SetPagePrivate(page);
2582 page_cache_get(page);
2583 set_page_private(page, EXTENT_PAGE_PRIVATE);
2588 * basic readpage implementation. Locked extent state structs are inserted
2589 * into the tree that are removed when the IO is done (by the end_io
2591 * XXX JDM: This needs looking at to ensure proper page locking
2593 static int __extent_read_full_page(struct extent_io_tree *tree,
2595 get_extent_t *get_extent,
2596 struct bio **bio, int mirror_num,
2597 unsigned long *bio_flags)
2599 struct inode *inode = page->mapping->host;
2600 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2601 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2605 u64 last_byte = i_size_read(inode);
2609 struct extent_map *em;
2610 struct block_device *bdev;
2611 struct btrfs_ordered_extent *ordered;
2614 size_t pg_offset = 0;
2616 size_t disk_io_size;
2617 size_t blocksize = inode->i_sb->s_blocksize;
2618 unsigned long this_bio_flag = 0;
2620 set_page_extent_mapped(page);
2622 if (!PageUptodate(page)) {
2623 if (cleancache_get_page(page) == 0) {
2624 BUG_ON(blocksize != PAGE_SIZE);
2631 lock_extent(tree, start, end);
2632 ordered = btrfs_lookup_ordered_extent(inode, start);
2635 unlock_extent(tree, start, end);
2636 btrfs_start_ordered_extent(inode, ordered, 1);
2637 btrfs_put_ordered_extent(ordered);
2640 if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
2642 size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
2645 iosize = PAGE_CACHE_SIZE - zero_offset;
2646 userpage = kmap_atomic(page);
2647 memset(userpage + zero_offset, 0, iosize);
2648 flush_dcache_page(page);
2649 kunmap_atomic(userpage);
2652 while (cur <= end) {
2653 if (cur >= last_byte) {
2655 struct extent_state *cached = NULL;
2657 iosize = PAGE_CACHE_SIZE - pg_offset;
2658 userpage = kmap_atomic(page);
2659 memset(userpage + pg_offset, 0, iosize);
2660 flush_dcache_page(page);
2661 kunmap_atomic(userpage);
2662 set_extent_uptodate(tree, cur, cur + iosize - 1,
2664 unlock_extent_cached(tree, cur, cur + iosize - 1,
2668 em = get_extent(inode, page, pg_offset, cur,
2670 if (IS_ERR_OR_NULL(em)) {
2672 unlock_extent(tree, cur, end);
2675 extent_offset = cur - em->start;
2676 BUG_ON(extent_map_end(em) <= cur);
2679 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2680 this_bio_flag = EXTENT_BIO_COMPRESSED;
2681 extent_set_compress_type(&this_bio_flag,
2685 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2686 cur_end = min(extent_map_end(em) - 1, end);
2687 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2688 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2689 disk_io_size = em->block_len;
2690 sector = em->block_start >> 9;
2692 sector = (em->block_start + extent_offset) >> 9;
2693 disk_io_size = iosize;
2696 block_start = em->block_start;
2697 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2698 block_start = EXTENT_MAP_HOLE;
2699 free_extent_map(em);
2702 /* we've found a hole, just zero and go on */
2703 if (block_start == EXTENT_MAP_HOLE) {
2705 struct extent_state *cached = NULL;
2707 userpage = kmap_atomic(page);
2708 memset(userpage + pg_offset, 0, iosize);
2709 flush_dcache_page(page);
2710 kunmap_atomic(userpage);
2712 set_extent_uptodate(tree, cur, cur + iosize - 1,
2714 unlock_extent_cached(tree, cur, cur + iosize - 1,
2717 pg_offset += iosize;
2720 /* the get_extent function already copied into the page */
2721 if (test_range_bit(tree, cur, cur_end,
2722 EXTENT_UPTODATE, 1, NULL)) {
2723 check_page_uptodate(tree, page);
2724 unlock_extent(tree, cur, cur + iosize - 1);
2726 pg_offset += iosize;
2729 /* we have an inline extent but it didn't get marked up
2730 * to date. Error out
2732 if (block_start == EXTENT_MAP_INLINE) {
2734 unlock_extent(tree, cur, cur + iosize - 1);
2736 pg_offset += iosize;
2741 if (tree->ops && tree->ops->readpage_io_hook) {
2742 ret = tree->ops->readpage_io_hook(page, cur,
2746 unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
2748 ret = submit_extent_page(READ, tree, page,
2749 sector, disk_io_size, pg_offset,
2751 end_bio_extent_readpage, mirror_num,
2754 BUG_ON(ret == -ENOMEM);
2756 *bio_flags = this_bio_flag;
2761 pg_offset += iosize;
2765 if (!PageError(page))
2766 SetPageUptodate(page);
2772 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
2773 get_extent_t *get_extent, int mirror_num)
2775 struct bio *bio = NULL;
2776 unsigned long bio_flags = 0;
2779 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
2782 ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
2786 static noinline void update_nr_written(struct page *page,
2787 struct writeback_control *wbc,
2788 unsigned long nr_written)
2790 wbc->nr_to_write -= nr_written;
2791 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
2792 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
2793 page->mapping->writeback_index = page->index + nr_written;
2797 * the writepage semantics are similar to regular writepage. extent
2798 * records are inserted to lock ranges in the tree, and as dirty areas
2799 * are found, they are marked writeback. Then the lock bits are removed
2800 * and the end_io handler clears the writeback ranges
2802 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
2805 struct inode *inode = page->mapping->host;
2806 struct extent_page_data *epd = data;
2807 struct extent_io_tree *tree = epd->tree;
2808 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2810 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2814 u64 last_byte = i_size_read(inode);
2818 struct extent_state *cached_state = NULL;
2819 struct extent_map *em;
2820 struct block_device *bdev;
2823 size_t pg_offset = 0;
2825 loff_t i_size = i_size_read(inode);
2826 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
2832 unsigned long nr_written = 0;
2833 bool fill_delalloc = true;
2835 if (wbc->sync_mode == WB_SYNC_ALL)
2836 write_flags = WRITE_SYNC;
2838 write_flags = WRITE;
2840 trace___extent_writepage(page, inode, wbc);
2842 WARN_ON(!PageLocked(page));
2844 ClearPageError(page);
2846 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2847 if (page->index > end_index ||
2848 (page->index == end_index && !pg_offset)) {
2849 page->mapping->a_ops->invalidatepage(page, 0);
2854 if (page->index == end_index) {
2857 userpage = kmap_atomic(page);
2858 memset(userpage + pg_offset, 0,
2859 PAGE_CACHE_SIZE - pg_offset);
2860 kunmap_atomic(userpage);
2861 flush_dcache_page(page);
2865 set_page_extent_mapped(page);
2867 if (!tree->ops || !tree->ops->fill_delalloc)
2868 fill_delalloc = false;
2870 delalloc_start = start;
2873 if (!epd->extent_locked && fill_delalloc) {
2874 u64 delalloc_to_write = 0;
2876 * make sure the wbc mapping index is at least updated
2879 update_nr_written(page, wbc, 0);
2881 while (delalloc_end < page_end) {
2882 nr_delalloc = find_lock_delalloc_range(inode, tree,
2887 if (nr_delalloc == 0) {
2888 delalloc_start = delalloc_end + 1;
2891 ret = tree->ops->fill_delalloc(inode, page,
2896 /* File system has been set read-only */
2902 * delalloc_end is already one less than the total
2903 * length, so we don't subtract one from
2906 delalloc_to_write += (delalloc_end - delalloc_start +
2909 delalloc_start = delalloc_end + 1;
2911 if (wbc->nr_to_write < delalloc_to_write) {
2914 if (delalloc_to_write < thresh * 2)
2915 thresh = delalloc_to_write;
2916 wbc->nr_to_write = min_t(u64, delalloc_to_write,
2920 /* did the fill delalloc function already unlock and start
2926 * we've unlocked the page, so we can't update
2927 * the mapping's writeback index, just update
2930 wbc->nr_to_write -= nr_written;
2934 if (tree->ops && tree->ops->writepage_start_hook) {
2935 ret = tree->ops->writepage_start_hook(page, start,
2938 /* Fixup worker will requeue */
2940 wbc->pages_skipped++;
2942 redirty_page_for_writepage(wbc, page);
2943 update_nr_written(page, wbc, nr_written);
2951 * we don't want to touch the inode after unlocking the page,
2952 * so we update the mapping writeback index now
2954 update_nr_written(page, wbc, nr_written + 1);
2957 if (last_byte <= start) {
2958 if (tree->ops && tree->ops->writepage_end_io_hook)
2959 tree->ops->writepage_end_io_hook(page, start,
2964 blocksize = inode->i_sb->s_blocksize;
2966 while (cur <= end) {
2967 if (cur >= last_byte) {
2968 if (tree->ops && tree->ops->writepage_end_io_hook)
2969 tree->ops->writepage_end_io_hook(page, cur,
2973 em = epd->get_extent(inode, page, pg_offset, cur,
2975 if (IS_ERR_OR_NULL(em)) {
2980 extent_offset = cur - em->start;
2981 BUG_ON(extent_map_end(em) <= cur);
2983 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2984 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2985 sector = (em->block_start + extent_offset) >> 9;
2987 block_start = em->block_start;
2988 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
2989 free_extent_map(em);
2993 * compressed and inline extents are written through other
2996 if (compressed || block_start == EXTENT_MAP_HOLE ||
2997 block_start == EXTENT_MAP_INLINE) {
2999 * end_io notification does not happen here for
3000 * compressed extents
3002 if (!compressed && tree->ops &&
3003 tree->ops->writepage_end_io_hook)
3004 tree->ops->writepage_end_io_hook(page, cur,
3007 else if (compressed) {
3008 /* we don't want to end_page_writeback on
3009 * a compressed extent. this happens
3016 pg_offset += iosize;
3019 /* leave this out until we have a page_mkwrite call */
3020 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
3021 EXTENT_DIRTY, 0, NULL)) {
3023 pg_offset += iosize;
3027 if (tree->ops && tree->ops->writepage_io_hook) {
3028 ret = tree->ops->writepage_io_hook(page, cur,
3036 unsigned long max_nr = end_index + 1;
3038 set_range_writeback(tree, cur, cur + iosize - 1);
3039 if (!PageWriteback(page)) {
3040 printk(KERN_ERR "btrfs warning page %lu not "
3041 "writeback, cur %llu end %llu\n",
3042 page->index, (unsigned long long)cur,
3043 (unsigned long long)end);
3046 ret = submit_extent_page(write_flags, tree, page,
3047 sector, iosize, pg_offset,
3048 bdev, &epd->bio, max_nr,
3049 end_bio_extent_writepage,
3055 pg_offset += iosize;
3060 /* make sure the mapping tag for page dirty gets cleared */
3061 set_page_writeback(page);
3062 end_page_writeback(page);
3068 /* drop our reference on any cached states */
3069 free_extent_state(cached_state);
3073 static int eb_wait(void *word)
3079 static void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3081 wait_on_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK, eb_wait,
3082 TASK_UNINTERRUPTIBLE);
3085 static int lock_extent_buffer_for_io(struct extent_buffer *eb,
3086 struct btrfs_fs_info *fs_info,
3087 struct extent_page_data *epd)
3089 unsigned long i, num_pages;
3093 if (!btrfs_try_tree_write_lock(eb)) {
3095 flush_write_bio(epd);
3096 btrfs_tree_lock(eb);
3099 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3100 btrfs_tree_unlock(eb);
3104 flush_write_bio(epd);
3108 wait_on_extent_buffer_writeback(eb);
3109 btrfs_tree_lock(eb);
3110 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3112 btrfs_tree_unlock(eb);
3117 * We need to do this to prevent races in people who check if the eb is
3118 * under IO since we can end up having no IO bits set for a short period
3121 spin_lock(&eb->refs_lock);
3122 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3123 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3124 spin_unlock(&eb->refs_lock);
3125 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3126 spin_lock(&fs_info->delalloc_lock);
3127 if (fs_info->dirty_metadata_bytes >= eb->len)
3128 fs_info->dirty_metadata_bytes -= eb->len;
3131 spin_unlock(&fs_info->delalloc_lock);
3134 spin_unlock(&eb->refs_lock);
3137 btrfs_tree_unlock(eb);
3142 num_pages = num_extent_pages(eb->start, eb->len);
3143 for (i = 0; i < num_pages; i++) {
3144 struct page *p = extent_buffer_page(eb, i);
3146 if (!trylock_page(p)) {
3148 flush_write_bio(epd);
3158 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3160 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3161 smp_mb__after_clear_bit();
3162 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3165 static void end_bio_extent_buffer_writepage(struct bio *bio, int err)
3167 int uptodate = err == 0;
3168 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
3169 struct extent_buffer *eb;
3173 struct page *page = bvec->bv_page;
3176 eb = (struct extent_buffer *)page->private;
3178 done = atomic_dec_and_test(&eb->io_pages);
3180 if (!uptodate || test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) {
3181 set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3182 ClearPageUptodate(page);
3186 end_page_writeback(page);
3191 end_extent_buffer_writeback(eb);
3192 } while (bvec >= bio->bi_io_vec);
3198 static int write_one_eb(struct extent_buffer *eb,
3199 struct btrfs_fs_info *fs_info,
3200 struct writeback_control *wbc,
3201 struct extent_page_data *epd)
3203 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3204 u64 offset = eb->start;
3205 unsigned long i, num_pages;
3206 unsigned long bio_flags = 0;
3207 int rw = (epd->sync_io ? WRITE_SYNC : WRITE);
3210 clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3211 num_pages = num_extent_pages(eb->start, eb->len);
3212 atomic_set(&eb->io_pages, num_pages);
3213 if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
3214 bio_flags = EXTENT_BIO_TREE_LOG;
3216 for (i = 0; i < num_pages; i++) {
3217 struct page *p = extent_buffer_page(eb, i);
3219 clear_page_dirty_for_io(p);
3220 set_page_writeback(p);
3221 ret = submit_extent_page(rw, eb->tree, p, offset >> 9,
3222 PAGE_CACHE_SIZE, 0, bdev, &epd->bio,
3223 -1, end_bio_extent_buffer_writepage,
3224 0, epd->bio_flags, bio_flags);
3225 epd->bio_flags = bio_flags;
3227 set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3229 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3230 end_extent_buffer_writeback(eb);
3234 offset += PAGE_CACHE_SIZE;
3235 update_nr_written(p, wbc, 1);
3239 if (unlikely(ret)) {
3240 for (; i < num_pages; i++) {
3241 struct page *p = extent_buffer_page(eb, i);
3249 int btree_write_cache_pages(struct address_space *mapping,
3250 struct writeback_control *wbc)
3252 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3253 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3254 struct extent_buffer *eb, *prev_eb = NULL;
3255 struct extent_page_data epd = {
3259 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3264 int nr_to_write_done = 0;
3265 struct pagevec pvec;
3268 pgoff_t end; /* Inclusive */
3272 pagevec_init(&pvec, 0);
3273 if (wbc->range_cyclic) {
3274 index = mapping->writeback_index; /* Start from prev offset */
3277 index = wbc->range_start >> PAGE_CACHE_SHIFT;
3278 end = wbc->range_end >> PAGE_CACHE_SHIFT;
3281 if (wbc->sync_mode == WB_SYNC_ALL)
3282 tag = PAGECACHE_TAG_TOWRITE;
3284 tag = PAGECACHE_TAG_DIRTY;
3286 if (wbc->sync_mode == WB_SYNC_ALL)
3287 tag_pages_for_writeback(mapping, index, end);
3288 while (!done && !nr_to_write_done && (index <= end) &&
3289 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3290 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3294 for (i = 0; i < nr_pages; i++) {
3295 struct page *page = pvec.pages[i];
3297 if (!PagePrivate(page))
3300 if (!wbc->range_cyclic && page->index > end) {
3305 spin_lock(&mapping->private_lock);
3306 if (!PagePrivate(page)) {
3307 spin_unlock(&mapping->private_lock);
3311 eb = (struct extent_buffer *)page->private;
3314 * Shouldn't happen and normally this would be a BUG_ON
3315 * but no sense in crashing the users box for something
3316 * we can survive anyway.
3319 spin_unlock(&mapping->private_lock);
3324 if (eb == prev_eb) {
3325 spin_unlock(&mapping->private_lock);
3329 ret = atomic_inc_not_zero(&eb->refs);
3330 spin_unlock(&mapping->private_lock);
3335 ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
3337 free_extent_buffer(eb);
3341 ret = write_one_eb(eb, fs_info, wbc, &epd);
3344 free_extent_buffer(eb);
3347 free_extent_buffer(eb);
3350 * the filesystem may choose to bump up nr_to_write.
3351 * We have to make sure to honor the new nr_to_write
3354 nr_to_write_done = wbc->nr_to_write <= 0;
3356 pagevec_release(&pvec);
3359 if (!scanned && !done) {
3361 * We hit the last page and there is more work to be done: wrap
3362 * back to the start of the file
3368 flush_write_bio(&epd);
3373 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3374 * @mapping: address space structure to write
3375 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3376 * @writepage: function called for each page
3377 * @data: data passed to writepage function
3379 * If a page is already under I/O, write_cache_pages() skips it, even
3380 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3381 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3382 * and msync() need to guarantee that all the data which was dirty at the time
3383 * the call was made get new I/O started against them. If wbc->sync_mode is
3384 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3385 * existing IO to complete.
3387 static int extent_write_cache_pages(struct extent_io_tree *tree,
3388 struct address_space *mapping,
3389 struct writeback_control *wbc,
3390 writepage_t writepage, void *data,
3391 void (*flush_fn)(void *))
3393 struct inode *inode = mapping->host;
3396 int nr_to_write_done = 0;
3397 struct pagevec pvec;
3400 pgoff_t end; /* Inclusive */
3405 * We have to hold onto the inode so that ordered extents can do their
3406 * work when the IO finishes. The alternative to this is failing to add
3407 * an ordered extent if the igrab() fails there and that is a huge pain
3408 * to deal with, so instead just hold onto the inode throughout the
3409 * writepages operation. If it fails here we are freeing up the inode
3410 * anyway and we'd rather not waste our time writing out stuff that is
3411 * going to be truncated anyway.
3416 pagevec_init(&pvec, 0);
3417 if (wbc->range_cyclic) {
3418 index = mapping->writeback_index; /* Start from prev offset */
3421 index = wbc->range_start >> PAGE_CACHE_SHIFT;
3422 end = wbc->range_end >> PAGE_CACHE_SHIFT;
3425 if (wbc->sync_mode == WB_SYNC_ALL)
3426 tag = PAGECACHE_TAG_TOWRITE;
3428 tag = PAGECACHE_TAG_DIRTY;
3430 if (wbc->sync_mode == WB_SYNC_ALL)
3431 tag_pages_for_writeback(mapping, index, end);
3432 while (!done && !nr_to_write_done && (index <= end) &&
3433 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3434 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3438 for (i = 0; i < nr_pages; i++) {
3439 struct page *page = pvec.pages[i];
3442 * At this point we hold neither mapping->tree_lock nor
3443 * lock on the page itself: the page may be truncated or
3444 * invalidated (changing page->mapping to NULL), or even
3445 * swizzled back from swapper_space to tmpfs file
3449 tree->ops->write_cache_pages_lock_hook) {
3450 tree->ops->write_cache_pages_lock_hook(page,
3453 if (!trylock_page(page)) {
3459 if (unlikely(page->mapping != mapping)) {
3464 if (!wbc->range_cyclic && page->index > end) {
3470 if (wbc->sync_mode != WB_SYNC_NONE) {
3471 if (PageWriteback(page))
3473 wait_on_page_writeback(page);
3476 if (PageWriteback(page) ||
3477 !clear_page_dirty_for_io(page)) {
3482 ret = (*writepage)(page, wbc, data);
3484 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
3492 * the filesystem may choose to bump up nr_to_write.
3493 * We have to make sure to honor the new nr_to_write
3496 nr_to_write_done = wbc->nr_to_write <= 0;
3498 pagevec_release(&pvec);
3501 if (!scanned && !done) {
3503 * We hit the last page and there is more work to be done: wrap
3504 * back to the start of the file
3510 btrfs_add_delayed_iput(inode);
3514 static void flush_epd_write_bio(struct extent_page_data *epd)
3523 ret = submit_one_bio(rw, epd->bio, 0, epd->bio_flags);
3524 BUG_ON(ret < 0); /* -ENOMEM */
3529 static noinline void flush_write_bio(void *data)
3531 struct extent_page_data *epd = data;
3532 flush_epd_write_bio(epd);
3535 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
3536 get_extent_t *get_extent,
3537 struct writeback_control *wbc)
3540 struct extent_page_data epd = {
3543 .get_extent = get_extent,
3545 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3549 ret = __extent_writepage(page, wbc, &epd);
3551 flush_epd_write_bio(&epd);
3555 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
3556 u64 start, u64 end, get_extent_t *get_extent,
3560 struct address_space *mapping = inode->i_mapping;
3562 unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
3565 struct extent_page_data epd = {
3568 .get_extent = get_extent,
3570 .sync_io = mode == WB_SYNC_ALL,
3573 struct writeback_control wbc_writepages = {
3575 .nr_to_write = nr_pages * 2,
3576 .range_start = start,
3577 .range_end = end + 1,
3580 while (start <= end) {
3581 page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
3582 if (clear_page_dirty_for_io(page))
3583 ret = __extent_writepage(page, &wbc_writepages, &epd);
3585 if (tree->ops && tree->ops->writepage_end_io_hook)
3586 tree->ops->writepage_end_io_hook(page, start,
3587 start + PAGE_CACHE_SIZE - 1,
3591 page_cache_release(page);
3592 start += PAGE_CACHE_SIZE;
3595 flush_epd_write_bio(&epd);
3599 int extent_writepages(struct extent_io_tree *tree,
3600 struct address_space *mapping,
3601 get_extent_t *get_extent,
3602 struct writeback_control *wbc)
3605 struct extent_page_data epd = {
3608 .get_extent = get_extent,
3610 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3614 ret = extent_write_cache_pages(tree, mapping, wbc,
3615 __extent_writepage, &epd,
3617 flush_epd_write_bio(&epd);
3621 int extent_readpages(struct extent_io_tree *tree,
3622 struct address_space *mapping,
3623 struct list_head *pages, unsigned nr_pages,
3624 get_extent_t get_extent)
3626 struct bio *bio = NULL;
3628 unsigned long bio_flags = 0;
3629 struct page *pagepool[16];
3634 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
3635 page = list_entry(pages->prev, struct page, lru);
3637 prefetchw(&page->flags);
3638 list_del(&page->lru);
3639 if (add_to_page_cache_lru(page, mapping,
3640 page->index, GFP_NOFS)) {
3641 page_cache_release(page);
3645 pagepool[nr++] = page;
3646 if (nr < ARRAY_SIZE(pagepool))
3648 for (i = 0; i < nr; i++) {
3649 __extent_read_full_page(tree, pagepool[i], get_extent,
3650 &bio, 0, &bio_flags);
3651 page_cache_release(pagepool[i]);
3655 for (i = 0; i < nr; i++) {
3656 __extent_read_full_page(tree, pagepool[i], get_extent,
3657 &bio, 0, &bio_flags);
3658 page_cache_release(pagepool[i]);
3661 BUG_ON(!list_empty(pages));
3663 return submit_one_bio(READ, bio, 0, bio_flags);
3668 * basic invalidatepage code, this waits on any locked or writeback
3669 * ranges corresponding to the page, and then deletes any extent state
3670 * records from the tree
3672 int extent_invalidatepage(struct extent_io_tree *tree,
3673 struct page *page, unsigned long offset)
3675 struct extent_state *cached_state = NULL;
3676 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
3677 u64 end = start + PAGE_CACHE_SIZE - 1;
3678 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
3680 start += (offset + blocksize - 1) & ~(blocksize - 1);
3684 lock_extent_bits(tree, start, end, 0, &cached_state);
3685 wait_on_page_writeback(page);
3686 clear_extent_bit(tree, start, end,
3687 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
3688 EXTENT_DO_ACCOUNTING,
3689 1, 1, &cached_state, GFP_NOFS);
3694 * a helper for releasepage, this tests for areas of the page that
3695 * are locked or under IO and drops the related state bits if it is safe
3698 int try_release_extent_state(struct extent_map_tree *map,
3699 struct extent_io_tree *tree, struct page *page,
3702 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
3703 u64 end = start + PAGE_CACHE_SIZE - 1;
3706 if (test_range_bit(tree, start, end,
3707 EXTENT_IOBITS, 0, NULL))
3710 if ((mask & GFP_NOFS) == GFP_NOFS)
3713 * at this point we can safely clear everything except the
3714 * locked bit and the nodatasum bit
3716 ret = clear_extent_bit(tree, start, end,
3717 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
3720 /* if clear_extent_bit failed for enomem reasons,
3721 * we can't allow the release to continue.
3732 * a helper for releasepage. As long as there are no locked extents
3733 * in the range corresponding to the page, both state records and extent
3734 * map records are removed
3736 int try_release_extent_mapping(struct extent_map_tree *map,
3737 struct extent_io_tree *tree, struct page *page,
3740 struct extent_map *em;
3741 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
3742 u64 end = start + PAGE_CACHE_SIZE - 1;
3744 if ((mask & __GFP_WAIT) &&
3745 page->mapping->host->i_size > 16 * 1024 * 1024) {
3747 while (start <= end) {
3748 len = end - start + 1;
3749 write_lock(&map->lock);
3750 em = lookup_extent_mapping(map, start, len);
3752 write_unlock(&map->lock);
3755 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
3756 em->start != start) {
3757 write_unlock(&map->lock);
3758 free_extent_map(em);
3761 if (!test_range_bit(tree, em->start,
3762 extent_map_end(em) - 1,
3763 EXTENT_LOCKED | EXTENT_WRITEBACK,
3765 remove_extent_mapping(map, em);
3766 /* once for the rb tree */
3767 free_extent_map(em);
3769 start = extent_map_end(em);
3770 write_unlock(&map->lock);
3773 free_extent_map(em);
3776 return try_release_extent_state(map, tree, page, mask);
3780 * helper function for fiemap, which doesn't want to see any holes.
3781 * This maps until we find something past 'last'
3783 static struct extent_map *get_extent_skip_holes(struct inode *inode,
3786 get_extent_t *get_extent)
3788 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
3789 struct extent_map *em;
3796 len = last - offset;
3799 len = (len + sectorsize - 1) & ~(sectorsize - 1);
3800 em = get_extent(inode, NULL, 0, offset, len, 0);
3801 if (IS_ERR_OR_NULL(em))
3804 /* if this isn't a hole return it */
3805 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
3806 em->block_start != EXTENT_MAP_HOLE) {
3810 /* this is a hole, advance to the next extent */
3811 offset = extent_map_end(em);
3812 free_extent_map(em);
3819 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3820 __u64 start, __u64 len, get_extent_t *get_extent)
3824 u64 max = start + len;
3828 u64 last_for_get_extent = 0;
3830 u64 isize = i_size_read(inode);
3831 struct btrfs_key found_key;
3832 struct extent_map *em = NULL;
3833 struct extent_state *cached_state = NULL;
3834 struct btrfs_path *path;
3835 struct btrfs_file_extent_item *item;
3840 unsigned long emflags;
3845 path = btrfs_alloc_path();
3848 path->leave_spinning = 1;
3850 start = ALIGN(start, BTRFS_I(inode)->root->sectorsize);
3851 len = ALIGN(len, BTRFS_I(inode)->root->sectorsize);
3854 * lookup the last file extent. We're not using i_size here
3855 * because there might be preallocation past i_size
3857 ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
3858 path, btrfs_ino(inode), -1, 0);
3860 btrfs_free_path(path);
3865 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3866 struct btrfs_file_extent_item);
3867 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
3868 found_type = btrfs_key_type(&found_key);
3870 /* No extents, but there might be delalloc bits */
3871 if (found_key.objectid != btrfs_ino(inode) ||
3872 found_type != BTRFS_EXTENT_DATA_KEY) {
3873 /* have to trust i_size as the end */
3875 last_for_get_extent = isize;
3878 * remember the start of the last extent. There are a
3879 * bunch of different factors that go into the length of the
3880 * extent, so its much less complex to remember where it started
3882 last = found_key.offset;
3883 last_for_get_extent = last + 1;
3885 btrfs_free_path(path);
3888 * we might have some extents allocated but more delalloc past those
3889 * extents. so, we trust isize unless the start of the last extent is
3894 last_for_get_extent = isize;
3897 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
3900 em = get_extent_skip_holes(inode, start, last_for_get_extent,
3910 u64 offset_in_extent;
3912 /* break if the extent we found is outside the range */
3913 if (em->start >= max || extent_map_end(em) < off)
3917 * get_extent may return an extent that starts before our
3918 * requested range. We have to make sure the ranges
3919 * we return to fiemap always move forward and don't
3920 * overlap, so adjust the offsets here
3922 em_start = max(em->start, off);
3925 * record the offset from the start of the extent
3926 * for adjusting the disk offset below
3928 offset_in_extent = em_start - em->start;
3929 em_end = extent_map_end(em);
3930 em_len = em_end - em_start;
3931 emflags = em->flags;
3936 * bump off for our next call to get_extent
3938 off = extent_map_end(em);
3942 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
3944 flags |= FIEMAP_EXTENT_LAST;
3945 } else if (em->block_start == EXTENT_MAP_INLINE) {
3946 flags |= (FIEMAP_EXTENT_DATA_INLINE |
3947 FIEMAP_EXTENT_NOT_ALIGNED);
3948 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
3949 flags |= (FIEMAP_EXTENT_DELALLOC |
3950 FIEMAP_EXTENT_UNKNOWN);
3952 disko = em->block_start + offset_in_extent;
3954 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
3955 flags |= FIEMAP_EXTENT_ENCODED;
3957 free_extent_map(em);
3959 if ((em_start >= last) || em_len == (u64)-1 ||
3960 (last == (u64)-1 && isize <= em_end)) {
3961 flags |= FIEMAP_EXTENT_LAST;
3965 /* now scan forward to see if this is really the last extent. */
3966 em = get_extent_skip_holes(inode, off, last_for_get_extent,
3973 flags |= FIEMAP_EXTENT_LAST;
3976 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
3982 free_extent_map(em);
3984 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len,
3985 &cached_state, GFP_NOFS);
3989 inline struct page *extent_buffer_page(struct extent_buffer *eb,
3992 return eb->pages[i];
3995 inline unsigned long num_extent_pages(u64 start, u64 len)
3997 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
3998 (start >> PAGE_CACHE_SHIFT);
4001 static void __free_extent_buffer(struct extent_buffer *eb)
4004 unsigned long flags;
4005 spin_lock_irqsave(&leak_lock, flags);
4006 list_del(&eb->leak_list);
4007 spin_unlock_irqrestore(&leak_lock, flags);
4009 if (eb->pages && eb->pages != eb->inline_pages)
4011 kmem_cache_free(extent_buffer_cache, eb);
4014 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
4019 struct extent_buffer *eb = NULL;
4021 unsigned long flags;
4024 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
4031 rwlock_init(&eb->lock);
4032 atomic_set(&eb->write_locks, 0);
4033 atomic_set(&eb->read_locks, 0);
4034 atomic_set(&eb->blocking_readers, 0);
4035 atomic_set(&eb->blocking_writers, 0);
4036 atomic_set(&eb->spinning_readers, 0);
4037 atomic_set(&eb->spinning_writers, 0);
4038 eb->lock_nested = 0;
4039 init_waitqueue_head(&eb->write_lock_wq);
4040 init_waitqueue_head(&eb->read_lock_wq);
4043 spin_lock_irqsave(&leak_lock, flags);
4044 list_add(&eb->leak_list, &buffers);
4045 spin_unlock_irqrestore(&leak_lock, flags);
4047 spin_lock_init(&eb->refs_lock);
4048 atomic_set(&eb->refs, 1);
4049 atomic_set(&eb->io_pages, 0);
4051 if (len > MAX_INLINE_EXTENT_BUFFER_SIZE) {
4052 struct page **pages;
4053 int num_pages = (len + PAGE_CACHE_SIZE - 1) >>
4055 pages = kzalloc(num_pages, mask);
4057 __free_extent_buffer(eb);
4062 eb->pages = eb->inline_pages;
4068 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4072 struct extent_buffer *new;
4073 unsigned long num_pages = num_extent_pages(src->start, src->len);
4075 new = __alloc_extent_buffer(NULL, src->start, src->len, GFP_ATOMIC);
4079 for (i = 0; i < num_pages; i++) {
4080 p = alloc_page(GFP_ATOMIC);
4082 attach_extent_buffer_page(new, p);
4083 WARN_ON(PageDirty(p));
4088 copy_extent_buffer(new, src, 0, 0, src->len);
4089 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4090 set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
4095 struct extent_buffer *alloc_dummy_extent_buffer(u64 start, unsigned long len)
4097 struct extent_buffer *eb;
4098 unsigned long num_pages = num_extent_pages(0, len);
4101 eb = __alloc_extent_buffer(NULL, start, len, GFP_ATOMIC);
4105 for (i = 0; i < num_pages; i++) {
4106 eb->pages[i] = alloc_page(GFP_ATOMIC);
4110 set_extent_buffer_uptodate(eb);
4111 btrfs_set_header_nritems(eb, 0);
4112 set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4116 for (i--; i > 0; i--)
4117 __free_page(eb->pages[i]);
4118 __free_extent_buffer(eb);
4122 static int extent_buffer_under_io(struct extent_buffer *eb)
4124 return (atomic_read(&eb->io_pages) ||
4125 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4126 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4130 * Helper for releasing extent buffer page.
4132 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
4133 unsigned long start_idx)
4135 unsigned long index;
4136 unsigned long num_pages;
4138 int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4140 BUG_ON(extent_buffer_under_io(eb));
4142 num_pages = num_extent_pages(eb->start, eb->len);
4143 index = start_idx + num_pages;
4144 if (start_idx >= index)
4149 page = extent_buffer_page(eb, index);
4150 if (page && mapped) {
4151 spin_lock(&page->mapping->private_lock);
4153 * We do this since we'll remove the pages after we've
4154 * removed the eb from the radix tree, so we could race
4155 * and have this page now attached to the new eb. So
4156 * only clear page_private if it's still connected to
4159 if (PagePrivate(page) &&
4160 page->private == (unsigned long)eb) {
4161 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4162 BUG_ON(PageDirty(page));
4163 BUG_ON(PageWriteback(page));
4165 * We need to make sure we haven't be attached
4168 ClearPagePrivate(page);
4169 set_page_private(page, 0);
4170 /* One for the page private */
4171 page_cache_release(page);
4173 spin_unlock(&page->mapping->private_lock);
4177 /* One for when we alloced the page */
4178 page_cache_release(page);
4180 } while (index != start_idx);
4184 * Helper for releasing the extent buffer.
4186 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4188 btrfs_release_extent_buffer_page(eb, 0);
4189 __free_extent_buffer(eb);
4192 static void check_buffer_tree_ref(struct extent_buffer *eb)
4194 /* the ref bit is tricky. We have to make sure it is set
4195 * if we have the buffer dirty. Otherwise the
4196 * code to free a buffer can end up dropping a dirty
4199 * Once the ref bit is set, it won't go away while the
4200 * buffer is dirty or in writeback, and it also won't
4201 * go away while we have the reference count on the
4204 * We can't just set the ref bit without bumping the
4205 * ref on the eb because free_extent_buffer might
4206 * see the ref bit and try to clear it. If this happens
4207 * free_extent_buffer might end up dropping our original
4208 * ref by mistake and freeing the page before we are able
4209 * to add one more ref.
4211 * So bump the ref count first, then set the bit. If someone
4212 * beat us to it, drop the ref we added.
4214 spin_lock(&eb->refs_lock);
4215 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4216 atomic_inc(&eb->refs);
4217 spin_unlock(&eb->refs_lock);
4220 static void mark_extent_buffer_accessed(struct extent_buffer *eb)
4222 unsigned long num_pages, i;
4224 check_buffer_tree_ref(eb);
4226 num_pages = num_extent_pages(eb->start, eb->len);
4227 for (i = 0; i < num_pages; i++) {
4228 struct page *p = extent_buffer_page(eb, i);
4229 mark_page_accessed(p);
4233 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
4234 u64 start, unsigned long len)
4236 unsigned long num_pages = num_extent_pages(start, len);
4238 unsigned long index = start >> PAGE_CACHE_SHIFT;
4239 struct extent_buffer *eb;
4240 struct extent_buffer *exists = NULL;
4242 struct address_space *mapping = tree->mapping;
4247 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4248 if (eb && atomic_inc_not_zero(&eb->refs)) {
4250 mark_extent_buffer_accessed(eb);
4255 eb = __alloc_extent_buffer(tree, start, len, GFP_NOFS);
4259 for (i = 0; i < num_pages; i++, index++) {
4260 p = find_or_create_page(mapping, index, GFP_NOFS);
4266 spin_lock(&mapping->private_lock);
4267 if (PagePrivate(p)) {
4269 * We could have already allocated an eb for this page
4270 * and attached one so lets see if we can get a ref on
4271 * the existing eb, and if we can we know it's good and
4272 * we can just return that one, else we know we can just
4273 * overwrite page->private.
4275 exists = (struct extent_buffer *)p->private;
4276 if (atomic_inc_not_zero(&exists->refs)) {
4277 spin_unlock(&mapping->private_lock);
4279 page_cache_release(p);
4280 mark_extent_buffer_accessed(exists);
4285 * Do this so attach doesn't complain and we need to
4286 * drop the ref the old guy had.
4288 ClearPagePrivate(p);
4289 WARN_ON(PageDirty(p));
4290 page_cache_release(p);
4292 attach_extent_buffer_page(eb, p);
4293 spin_unlock(&mapping->private_lock);
4294 WARN_ON(PageDirty(p));
4295 mark_page_accessed(p);
4297 if (!PageUptodate(p))
4301 * see below about how we avoid a nasty race with release page
4302 * and why we unlock later
4306 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4308 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
4312 spin_lock(&tree->buffer_lock);
4313 ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
4314 if (ret == -EEXIST) {
4315 exists = radix_tree_lookup(&tree->buffer,
4316 start >> PAGE_CACHE_SHIFT);
4317 if (!atomic_inc_not_zero(&exists->refs)) {
4318 spin_unlock(&tree->buffer_lock);
4319 radix_tree_preload_end();
4323 spin_unlock(&tree->buffer_lock);
4324 radix_tree_preload_end();
4325 mark_extent_buffer_accessed(exists);
4328 /* add one reference for the tree */
4329 check_buffer_tree_ref(eb);
4330 spin_unlock(&tree->buffer_lock);
4331 radix_tree_preload_end();
4334 * there is a race where release page may have
4335 * tried to find this extent buffer in the radix
4336 * but failed. It will tell the VM it is safe to
4337 * reclaim the, and it will clear the page private bit.
4338 * We must make sure to set the page private bit properly
4339 * after the extent buffer is in the radix tree so
4340 * it doesn't get lost
4342 SetPageChecked(eb->pages[0]);
4343 for (i = 1; i < num_pages; i++) {
4344 p = extent_buffer_page(eb, i);
4345 ClearPageChecked(p);
4348 unlock_page(eb->pages[0]);
4352 for (i = 0; i < num_pages; i++) {
4354 unlock_page(eb->pages[i]);
4357 WARN_ON(!atomic_dec_and_test(&eb->refs));
4358 btrfs_release_extent_buffer(eb);
4362 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
4363 u64 start, unsigned long len)
4365 struct extent_buffer *eb;
4368 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4369 if (eb && atomic_inc_not_zero(&eb->refs)) {
4371 mark_extent_buffer_accessed(eb);
4379 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
4381 struct extent_buffer *eb =
4382 container_of(head, struct extent_buffer, rcu_head);
4384 __free_extent_buffer(eb);
4387 /* Expects to have eb->eb_lock already held */
4388 static int release_extent_buffer(struct extent_buffer *eb, gfp_t mask)
4390 WARN_ON(atomic_read(&eb->refs) == 0);
4391 if (atomic_dec_and_test(&eb->refs)) {
4392 if (test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags)) {
4393 spin_unlock(&eb->refs_lock);
4395 struct extent_io_tree *tree = eb->tree;
4397 spin_unlock(&eb->refs_lock);
4399 spin_lock(&tree->buffer_lock);
4400 radix_tree_delete(&tree->buffer,
4401 eb->start >> PAGE_CACHE_SHIFT);
4402 spin_unlock(&tree->buffer_lock);
4405 /* Should be safe to release our pages at this point */
4406 btrfs_release_extent_buffer_page(eb, 0);
4407 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
4410 spin_unlock(&eb->refs_lock);
4415 void free_extent_buffer(struct extent_buffer *eb)
4420 spin_lock(&eb->refs_lock);
4421 if (atomic_read(&eb->refs) == 2 &&
4422 test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
4423 atomic_dec(&eb->refs);
4425 if (atomic_read(&eb->refs) == 2 &&
4426 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
4427 !extent_buffer_under_io(eb) &&
4428 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4429 atomic_dec(&eb->refs);
4432 * I know this is terrible, but it's temporary until we stop tracking
4433 * the uptodate bits and such for the extent buffers.
4435 release_extent_buffer(eb, GFP_ATOMIC);
4438 void free_extent_buffer_stale(struct extent_buffer *eb)
4443 spin_lock(&eb->refs_lock);
4444 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
4446 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
4447 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4448 atomic_dec(&eb->refs);
4449 release_extent_buffer(eb, GFP_NOFS);
4452 void clear_extent_buffer_dirty(struct extent_buffer *eb)
4455 unsigned long num_pages;
4458 num_pages = num_extent_pages(eb->start, eb->len);
4460 for (i = 0; i < num_pages; i++) {
4461 page = extent_buffer_page(eb, i);
4462 if (!PageDirty(page))
4466 WARN_ON(!PagePrivate(page));
4468 clear_page_dirty_for_io(page);
4469 spin_lock_irq(&page->mapping->tree_lock);
4470 if (!PageDirty(page)) {
4471 radix_tree_tag_clear(&page->mapping->page_tree,
4473 PAGECACHE_TAG_DIRTY);
4475 spin_unlock_irq(&page->mapping->tree_lock);
4476 ClearPageError(page);
4479 WARN_ON(atomic_read(&eb->refs) == 0);
4482 int set_extent_buffer_dirty(struct extent_buffer *eb)
4485 unsigned long num_pages;
4488 check_buffer_tree_ref(eb);
4490 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
4492 num_pages = num_extent_pages(eb->start, eb->len);
4493 WARN_ON(atomic_read(&eb->refs) == 0);
4494 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
4496 for (i = 0; i < num_pages; i++)
4497 set_page_dirty(extent_buffer_page(eb, i));
4501 static int range_straddles_pages(u64 start, u64 len)
4503 if (len < PAGE_CACHE_SIZE)
4505 if (start & (PAGE_CACHE_SIZE - 1))
4507 if ((start + len) & (PAGE_CACHE_SIZE - 1))
4512 int clear_extent_buffer_uptodate(struct extent_buffer *eb)
4516 unsigned long num_pages;
4518 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4519 num_pages = num_extent_pages(eb->start, eb->len);
4520 for (i = 0; i < num_pages; i++) {
4521 page = extent_buffer_page(eb, i);
4523 ClearPageUptodate(page);
4528 int set_extent_buffer_uptodate(struct extent_buffer *eb)
4532 unsigned long num_pages;
4534 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4535 num_pages = num_extent_pages(eb->start, eb->len);
4536 for (i = 0; i < num_pages; i++) {
4537 page = extent_buffer_page(eb, i);
4538 SetPageUptodate(page);
4543 int extent_range_uptodate(struct extent_io_tree *tree,
4548 int pg_uptodate = 1;
4550 unsigned long index;
4552 if (range_straddles_pages(start, end - start + 1)) {
4553 ret = test_range_bit(tree, start, end,
4554 EXTENT_UPTODATE, 1, NULL);
4558 while (start <= end) {
4559 index = start >> PAGE_CACHE_SHIFT;
4560 page = find_get_page(tree->mapping, index);
4563 uptodate = PageUptodate(page);
4564 page_cache_release(page);
4569 start += PAGE_CACHE_SIZE;
4574 int extent_buffer_uptodate(struct extent_buffer *eb)
4576 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4579 int read_extent_buffer_pages(struct extent_io_tree *tree,
4580 struct extent_buffer *eb, u64 start, int wait,
4581 get_extent_t *get_extent, int mirror_num)
4584 unsigned long start_i;
4588 int locked_pages = 0;
4589 int all_uptodate = 1;
4590 unsigned long num_pages;
4591 unsigned long num_reads = 0;
4592 struct bio *bio = NULL;
4593 unsigned long bio_flags = 0;
4595 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
4599 WARN_ON(start < eb->start);
4600 start_i = (start >> PAGE_CACHE_SHIFT) -
4601 (eb->start >> PAGE_CACHE_SHIFT);
4606 num_pages = num_extent_pages(eb->start, eb->len);
4607 for (i = start_i; i < num_pages; i++) {
4608 page = extent_buffer_page(eb, i);
4609 if (wait == WAIT_NONE) {
4610 if (!trylock_page(page))
4616 if (!PageUptodate(page)) {
4623 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4627 clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
4628 eb->read_mirror = 0;
4629 atomic_set(&eb->io_pages, num_reads);
4630 for (i = start_i; i < num_pages; i++) {
4631 page = extent_buffer_page(eb, i);
4632 if (!PageUptodate(page)) {
4633 ClearPageError(page);
4634 err = __extent_read_full_page(tree, page,
4636 mirror_num, &bio_flags);
4645 err = submit_one_bio(READ, bio, mirror_num, bio_flags);
4650 if (ret || wait != WAIT_COMPLETE)
4653 for (i = start_i; i < num_pages; i++) {
4654 page = extent_buffer_page(eb, i);
4655 wait_on_page_locked(page);
4656 if (!PageUptodate(page))
4664 while (locked_pages > 0) {
4665 page = extent_buffer_page(eb, i);
4673 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
4674 unsigned long start,
4681 char *dst = (char *)dstv;
4682 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4683 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4685 WARN_ON(start > eb->len);
4686 WARN_ON(start + len > eb->start + eb->len);
4688 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4691 page = extent_buffer_page(eb, i);
4693 cur = min(len, (PAGE_CACHE_SIZE - offset));
4694 kaddr = page_address(page);
4695 memcpy(dst, kaddr + offset, cur);
4704 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
4705 unsigned long min_len, char **map,
4706 unsigned long *map_start,
4707 unsigned long *map_len)
4709 size_t offset = start & (PAGE_CACHE_SIZE - 1);
4712 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4713 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4714 unsigned long end_i = (start_offset + start + min_len - 1) >>
4721 offset = start_offset;
4725 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
4728 if (start + min_len > eb->len) {
4729 printk(KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
4730 "wanted %lu %lu\n", (unsigned long long)eb->start,
4731 eb->len, start, min_len);
4736 p = extent_buffer_page(eb, i);
4737 kaddr = page_address(p);
4738 *map = kaddr + offset;
4739 *map_len = PAGE_CACHE_SIZE - offset;
4743 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
4744 unsigned long start,
4751 char *ptr = (char *)ptrv;
4752 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4753 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4756 WARN_ON(start > eb->len);
4757 WARN_ON(start + len > eb->start + eb->len);
4759 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4762 page = extent_buffer_page(eb, i);
4764 cur = min(len, (PAGE_CACHE_SIZE - offset));
4766 kaddr = page_address(page);
4767 ret = memcmp(ptr, kaddr + offset, cur);
4779 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
4780 unsigned long start, unsigned long len)
4786 char *src = (char *)srcv;
4787 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4788 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4790 WARN_ON(start > eb->len);
4791 WARN_ON(start + len > eb->start + eb->len);
4793 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4796 page = extent_buffer_page(eb, i);
4797 WARN_ON(!PageUptodate(page));
4799 cur = min(len, PAGE_CACHE_SIZE - offset);
4800 kaddr = page_address(page);
4801 memcpy(kaddr + offset, src, cur);
4810 void memset_extent_buffer(struct extent_buffer *eb, char c,
4811 unsigned long start, unsigned long len)
4817 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4818 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4820 WARN_ON(start > eb->len);
4821 WARN_ON(start + len > eb->start + eb->len);
4823 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4826 page = extent_buffer_page(eb, i);
4827 WARN_ON(!PageUptodate(page));
4829 cur = min(len, PAGE_CACHE_SIZE - offset);
4830 kaddr = page_address(page);
4831 memset(kaddr + offset, c, cur);
4839 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
4840 unsigned long dst_offset, unsigned long src_offset,
4843 u64 dst_len = dst->len;
4848 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4849 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4851 WARN_ON(src->len != dst_len);
4853 offset = (start_offset + dst_offset) &
4854 ((unsigned long)PAGE_CACHE_SIZE - 1);
4857 page = extent_buffer_page(dst, i);
4858 WARN_ON(!PageUptodate(page));
4860 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
4862 kaddr = page_address(page);
4863 read_extent_buffer(src, kaddr + offset, src_offset, cur);
4872 static void move_pages(struct page *dst_page, struct page *src_page,
4873 unsigned long dst_off, unsigned long src_off,
4876 char *dst_kaddr = page_address(dst_page);
4877 if (dst_page == src_page) {
4878 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
4880 char *src_kaddr = page_address(src_page);
4881 char *p = dst_kaddr + dst_off + len;
4882 char *s = src_kaddr + src_off + len;
4889 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
4891 unsigned long distance = (src > dst) ? src - dst : dst - src;
4892 return distance < len;
4895 static void copy_pages(struct page *dst_page, struct page *src_page,
4896 unsigned long dst_off, unsigned long src_off,
4899 char *dst_kaddr = page_address(dst_page);
4901 int must_memmove = 0;
4903 if (dst_page != src_page) {
4904 src_kaddr = page_address(src_page);
4906 src_kaddr = dst_kaddr;
4907 if (areas_overlap(src_off, dst_off, len))
4912 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
4914 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
4917 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
4918 unsigned long src_offset, unsigned long len)
4921 size_t dst_off_in_page;
4922 size_t src_off_in_page;
4923 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4924 unsigned long dst_i;
4925 unsigned long src_i;
4927 if (src_offset + len > dst->len) {
4928 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4929 "len %lu dst len %lu\n", src_offset, len, dst->len);
4932 if (dst_offset + len > dst->len) {
4933 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4934 "len %lu dst len %lu\n", dst_offset, len, dst->len);
4939 dst_off_in_page = (start_offset + dst_offset) &
4940 ((unsigned long)PAGE_CACHE_SIZE - 1);
4941 src_off_in_page = (start_offset + src_offset) &
4942 ((unsigned long)PAGE_CACHE_SIZE - 1);
4944 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4945 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
4947 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
4949 cur = min_t(unsigned long, cur,
4950 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
4952 copy_pages(extent_buffer_page(dst, dst_i),
4953 extent_buffer_page(dst, src_i),
4954 dst_off_in_page, src_off_in_page, cur);
4962 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
4963 unsigned long src_offset, unsigned long len)
4966 size_t dst_off_in_page;
4967 size_t src_off_in_page;
4968 unsigned long dst_end = dst_offset + len - 1;
4969 unsigned long src_end = src_offset + len - 1;
4970 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4971 unsigned long dst_i;
4972 unsigned long src_i;
4974 if (src_offset + len > dst->len) {
4975 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4976 "len %lu len %lu\n", src_offset, len, dst->len);
4979 if (dst_offset + len > dst->len) {
4980 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4981 "len %lu len %lu\n", dst_offset, len, dst->len);
4984 if (dst_offset < src_offset) {
4985 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
4989 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
4990 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
4992 dst_off_in_page = (start_offset + dst_end) &
4993 ((unsigned long)PAGE_CACHE_SIZE - 1);
4994 src_off_in_page = (start_offset + src_end) &
4995 ((unsigned long)PAGE_CACHE_SIZE - 1);
4997 cur = min_t(unsigned long, len, src_off_in_page + 1);
4998 cur = min(cur, dst_off_in_page + 1);
4999 move_pages(extent_buffer_page(dst, dst_i),
5000 extent_buffer_page(dst, src_i),
5001 dst_off_in_page - cur + 1,
5002 src_off_in_page - cur + 1, cur);
5010 int try_release_extent_buffer(struct page *page, gfp_t mask)
5012 struct extent_buffer *eb;
5015 * We need to make sure noboody is attaching this page to an eb right
5018 spin_lock(&page->mapping->private_lock);
5019 if (!PagePrivate(page)) {
5020 spin_unlock(&page->mapping->private_lock);
5024 eb = (struct extent_buffer *)page->private;
5028 * This is a little awful but should be ok, we need to make sure that
5029 * the eb doesn't disappear out from under us while we're looking at
5032 spin_lock(&eb->refs_lock);
5033 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5034 spin_unlock(&eb->refs_lock);
5035 spin_unlock(&page->mapping->private_lock);
5038 spin_unlock(&page->mapping->private_lock);
5040 if ((mask & GFP_NOFS) == GFP_NOFS)
5044 * If tree ref isn't set then we know the ref on this eb is a real ref,
5045 * so just return, this page will likely be freed soon anyway.
5047 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
5048 spin_unlock(&eb->refs_lock);
5052 return release_extent_buffer(eb, mask);