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 static struct kmem_cache *extent_state_cache;
24 static struct kmem_cache *extent_buffer_cache;
26 static LIST_HEAD(buffers);
27 static LIST_HEAD(states);
31 static DEFINE_SPINLOCK(leak_lock);
34 #define BUFFER_LRU_MAX 64
39 struct rb_node rb_node;
42 struct extent_page_data {
44 struct extent_io_tree *tree;
45 get_extent_t *get_extent;
47 /* tells writepage not to lock the state bits for this range
48 * it still does the unlocking
50 unsigned int extent_locked:1;
52 /* tells the submit_bio code to use a WRITE_SYNC */
53 unsigned int sync_io:1;
56 int __init extent_io_init(void)
58 extent_state_cache = kmem_cache_create("extent_state",
59 sizeof(struct extent_state), 0,
60 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
61 if (!extent_state_cache)
64 extent_buffer_cache = kmem_cache_create("extent_buffers",
65 sizeof(struct extent_buffer), 0,
66 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
67 if (!extent_buffer_cache)
68 goto free_state_cache;
72 kmem_cache_destroy(extent_state_cache);
76 void extent_io_exit(void)
78 struct extent_state *state;
79 struct extent_buffer *eb;
81 while (!list_empty(&states)) {
82 state = list_entry(states.next, struct extent_state, leak_list);
83 printk(KERN_ERR "btrfs state leak: start %llu end %llu "
84 "state %lu in tree %p refs %d\n",
85 (unsigned long long)state->start,
86 (unsigned long long)state->end,
87 state->state, state->tree, atomic_read(&state->refs));
88 list_del(&state->leak_list);
89 kmem_cache_free(extent_state_cache, state);
93 while (!list_empty(&buffers)) {
94 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
95 printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
96 "refs %d\n", (unsigned long long)eb->start,
97 eb->len, atomic_read(&eb->refs));
98 list_del(&eb->leak_list);
99 kmem_cache_free(extent_buffer_cache, eb);
101 if (extent_state_cache)
102 kmem_cache_destroy(extent_state_cache);
103 if (extent_buffer_cache)
104 kmem_cache_destroy(extent_buffer_cache);
107 void extent_io_tree_init(struct extent_io_tree *tree,
108 struct address_space *mapping)
110 tree->state = RB_ROOT;
111 INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
113 tree->dirty_bytes = 0;
114 spin_lock_init(&tree->lock);
115 spin_lock_init(&tree->buffer_lock);
116 tree->mapping = mapping;
119 static struct extent_state *alloc_extent_state(gfp_t mask)
121 struct extent_state *state;
126 state = kmem_cache_alloc(extent_state_cache, mask);
133 spin_lock_irqsave(&leak_lock, flags);
134 list_add(&state->leak_list, &states);
135 spin_unlock_irqrestore(&leak_lock, flags);
137 atomic_set(&state->refs, 1);
138 init_waitqueue_head(&state->wq);
142 void free_extent_state(struct extent_state *state)
146 if (atomic_dec_and_test(&state->refs)) {
150 WARN_ON(state->tree);
152 spin_lock_irqsave(&leak_lock, flags);
153 list_del(&state->leak_list);
154 spin_unlock_irqrestore(&leak_lock, flags);
156 kmem_cache_free(extent_state_cache, state);
160 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
161 struct rb_node *node)
163 struct rb_node **p = &root->rb_node;
164 struct rb_node *parent = NULL;
165 struct tree_entry *entry;
169 entry = rb_entry(parent, struct tree_entry, rb_node);
171 if (offset < entry->start)
173 else if (offset > entry->end)
179 entry = rb_entry(node, struct tree_entry, rb_node);
180 rb_link_node(node, parent, p);
181 rb_insert_color(node, root);
185 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
186 struct rb_node **prev_ret,
187 struct rb_node **next_ret)
189 struct rb_root *root = &tree->state;
190 struct rb_node *n = root->rb_node;
191 struct rb_node *prev = NULL;
192 struct rb_node *orig_prev = NULL;
193 struct tree_entry *entry;
194 struct tree_entry *prev_entry = NULL;
197 entry = rb_entry(n, struct tree_entry, rb_node);
201 if (offset < entry->start)
203 else if (offset > entry->end)
211 while (prev && offset > prev_entry->end) {
212 prev = rb_next(prev);
213 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
220 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
221 while (prev && offset < prev_entry->start) {
222 prev = rb_prev(prev);
223 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
230 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
233 struct rb_node *prev = NULL;
236 ret = __etree_search(tree, offset, &prev, NULL);
242 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
243 struct extent_state *other)
245 if (tree->ops && tree->ops->merge_extent_hook)
246 tree->ops->merge_extent_hook(tree->mapping->host, new,
251 * utility function to look for merge candidates inside a given range.
252 * Any extents with matching state are merged together into a single
253 * extent in the tree. Extents with EXTENT_IO in their state field
254 * are not merged because the end_io handlers need to be able to do
255 * operations on them without sleeping (or doing allocations/splits).
257 * This should be called with the tree lock held.
259 static void merge_state(struct extent_io_tree *tree,
260 struct extent_state *state)
262 struct extent_state *other;
263 struct rb_node *other_node;
265 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
268 other_node = rb_prev(&state->rb_node);
270 other = rb_entry(other_node, struct extent_state, rb_node);
271 if (other->end == state->start - 1 &&
272 other->state == state->state) {
273 merge_cb(tree, state, other);
274 state->start = other->start;
276 rb_erase(&other->rb_node, &tree->state);
277 free_extent_state(other);
280 other_node = rb_next(&state->rb_node);
282 other = rb_entry(other_node, struct extent_state, rb_node);
283 if (other->start == state->end + 1 &&
284 other->state == state->state) {
285 merge_cb(tree, state, other);
286 state->end = other->end;
288 rb_erase(&other->rb_node, &tree->state);
289 free_extent_state(other);
294 static void set_state_cb(struct extent_io_tree *tree,
295 struct extent_state *state, int *bits)
297 if (tree->ops && tree->ops->set_bit_hook)
298 tree->ops->set_bit_hook(tree->mapping->host, state, bits);
301 static void clear_state_cb(struct extent_io_tree *tree,
302 struct extent_state *state, int *bits)
304 if (tree->ops && tree->ops->clear_bit_hook)
305 tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
308 static void set_state_bits(struct extent_io_tree *tree,
309 struct extent_state *state, int *bits);
312 * insert an extent_state struct into the tree. 'bits' are set on the
313 * struct before it is inserted.
315 * This may return -EEXIST if the extent is already there, in which case the
316 * state struct is freed.
318 * The tree lock is not taken internally. This is a utility function and
319 * probably isn't what you want to call (see set/clear_extent_bit).
321 static int insert_state(struct extent_io_tree *tree,
322 struct extent_state *state, u64 start, u64 end,
325 struct rb_node *node;
328 printk(KERN_ERR "btrfs end < start %llu %llu\n",
329 (unsigned long long)end,
330 (unsigned long long)start);
333 state->start = start;
336 set_state_bits(tree, state, bits);
338 node = tree_insert(&tree->state, end, &state->rb_node);
340 struct extent_state *found;
341 found = rb_entry(node, struct extent_state, rb_node);
342 printk(KERN_ERR "btrfs found node %llu %llu on insert of "
343 "%llu %llu\n", (unsigned long long)found->start,
344 (unsigned long long)found->end,
345 (unsigned long long)start, (unsigned long long)end);
349 merge_state(tree, state);
353 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
356 if (tree->ops && tree->ops->split_extent_hook)
357 tree->ops->split_extent_hook(tree->mapping->host, orig, split);
361 * split a given extent state struct in two, inserting the preallocated
362 * struct 'prealloc' as the newly created second half. 'split' indicates an
363 * offset inside 'orig' where it should be split.
366 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
367 * are two extent state structs in the tree:
368 * prealloc: [orig->start, split - 1]
369 * orig: [ split, orig->end ]
371 * The tree locks are not taken by this function. They need to be held
374 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
375 struct extent_state *prealloc, u64 split)
377 struct rb_node *node;
379 split_cb(tree, orig, split);
381 prealloc->start = orig->start;
382 prealloc->end = split - 1;
383 prealloc->state = orig->state;
386 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
388 free_extent_state(prealloc);
391 prealloc->tree = tree;
396 * utility function to clear some bits in an extent state struct.
397 * it will optionally wake up any one waiting on this state (wake == 1), or
398 * forcibly remove the state from the tree (delete == 1).
400 * If no bits are set on the state struct after clearing things, the
401 * struct is freed and removed from the tree
403 static int clear_state_bit(struct extent_io_tree *tree,
404 struct extent_state *state,
407 int bits_to_clear = *bits & ~EXTENT_CTLBITS;
408 int ret = state->state & bits_to_clear;
410 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
411 u64 range = state->end - state->start + 1;
412 WARN_ON(range > tree->dirty_bytes);
413 tree->dirty_bytes -= range;
415 clear_state_cb(tree, state, bits);
416 state->state &= ~bits_to_clear;
419 if (state->state == 0) {
421 rb_erase(&state->rb_node, &tree->state);
423 free_extent_state(state);
428 merge_state(tree, state);
433 static struct extent_state *
434 alloc_extent_state_atomic(struct extent_state *prealloc)
437 prealloc = alloc_extent_state(GFP_ATOMIC);
443 * clear some bits on a range in the tree. This may require splitting
444 * or inserting elements in the tree, so the gfp mask is used to
445 * indicate which allocations or sleeping are allowed.
447 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
448 * the given range from the tree regardless of state (ie for truncate).
450 * the range [start, end] is inclusive.
452 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
453 * bits were already set, or zero if none of the bits were already set.
455 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
456 int bits, int wake, int delete,
457 struct extent_state **cached_state,
460 struct extent_state *state;
461 struct extent_state *cached;
462 struct extent_state *prealloc = NULL;
463 struct rb_node *next_node;
464 struct rb_node *node;
471 bits |= ~EXTENT_CTLBITS;
472 bits |= EXTENT_FIRST_DELALLOC;
474 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
477 if (!prealloc && (mask & __GFP_WAIT)) {
478 prealloc = alloc_extent_state(mask);
483 spin_lock(&tree->lock);
485 cached = *cached_state;
488 *cached_state = NULL;
492 if (cached && cached->tree && cached->start <= start &&
493 cached->end > start) {
495 atomic_dec(&cached->refs);
500 free_extent_state(cached);
503 * this search will find the extents that end after
506 node = tree_search(tree, start);
509 state = rb_entry(node, struct extent_state, rb_node);
511 if (state->start > end)
513 WARN_ON(state->end < start);
514 last_end = state->end;
517 * | ---- desired range ---- |
519 * | ------------- state -------------- |
521 * We need to split the extent we found, and may flip
522 * bits on second half.
524 * If the extent we found extends past our range, we
525 * just split and search again. It'll get split again
526 * the next time though.
528 * If the extent we found is inside our range, we clear
529 * the desired bit on it.
532 if (state->start < start) {
533 prealloc = alloc_extent_state_atomic(prealloc);
535 err = split_state(tree, state, prealloc, start);
536 BUG_ON(err == -EEXIST);
540 if (state->end <= end) {
541 set |= clear_state_bit(tree, state, &bits, wake);
542 if (last_end == (u64)-1)
544 start = last_end + 1;
549 * | ---- desired range ---- |
551 * We need to split the extent, and clear the bit
554 if (state->start <= end && state->end > end) {
555 prealloc = alloc_extent_state_atomic(prealloc);
557 err = split_state(tree, state, prealloc, end + 1);
558 BUG_ON(err == -EEXIST);
562 set |= clear_state_bit(tree, prealloc, &bits, wake);
568 if (state->end < end && prealloc && !need_resched())
569 next_node = rb_next(&state->rb_node);
573 set |= clear_state_bit(tree, state, &bits, wake);
574 if (last_end == (u64)-1)
576 start = last_end + 1;
577 if (start <= end && next_node) {
578 state = rb_entry(next_node, struct extent_state,
580 if (state->start == start)
586 spin_unlock(&tree->lock);
588 free_extent_state(prealloc);
595 spin_unlock(&tree->lock);
596 if (mask & __GFP_WAIT)
601 static int wait_on_state(struct extent_io_tree *tree,
602 struct extent_state *state)
603 __releases(tree->lock)
604 __acquires(tree->lock)
607 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
608 spin_unlock(&tree->lock);
610 spin_lock(&tree->lock);
611 finish_wait(&state->wq, &wait);
616 * waits for one or more bits to clear on a range in the state tree.
617 * The range [start, end] is inclusive.
618 * The tree lock is taken by this function
620 int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
622 struct extent_state *state;
623 struct rb_node *node;
625 spin_lock(&tree->lock);
629 * this search will find all the extents that end after
632 node = tree_search(tree, start);
636 state = rb_entry(node, struct extent_state, rb_node);
638 if (state->start > end)
641 if (state->state & bits) {
642 start = state->start;
643 atomic_inc(&state->refs);
644 wait_on_state(tree, state);
645 free_extent_state(state);
648 start = state->end + 1;
653 cond_resched_lock(&tree->lock);
656 spin_unlock(&tree->lock);
660 static void set_state_bits(struct extent_io_tree *tree,
661 struct extent_state *state,
664 int bits_to_set = *bits & ~EXTENT_CTLBITS;
666 set_state_cb(tree, state, bits);
667 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
668 u64 range = state->end - state->start + 1;
669 tree->dirty_bytes += range;
671 state->state |= bits_to_set;
674 static void cache_state(struct extent_state *state,
675 struct extent_state **cached_ptr)
677 if (cached_ptr && !(*cached_ptr)) {
678 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
680 atomic_inc(&state->refs);
685 static void uncache_state(struct extent_state **cached_ptr)
687 if (cached_ptr && (*cached_ptr)) {
688 struct extent_state *state = *cached_ptr;
690 free_extent_state(state);
695 * set some bits on a range in the tree. This may require allocations or
696 * sleeping, so the gfp mask is used to indicate what is allowed.
698 * If any of the exclusive bits are set, this will fail with -EEXIST if some
699 * part of the range already has the desired bits set. The start of the
700 * existing range is returned in failed_start in this case.
702 * [start, end] is inclusive This takes the tree lock.
705 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
706 int bits, int exclusive_bits, u64 *failed_start,
707 struct extent_state **cached_state, gfp_t mask)
709 struct extent_state *state;
710 struct extent_state *prealloc = NULL;
711 struct rb_node *node;
716 bits |= EXTENT_FIRST_DELALLOC;
718 if (!prealloc && (mask & __GFP_WAIT)) {
719 prealloc = alloc_extent_state(mask);
723 spin_lock(&tree->lock);
724 if (cached_state && *cached_state) {
725 state = *cached_state;
726 if (state->start <= start && state->end > start &&
728 node = &state->rb_node;
733 * this search will find all the extents that end after
736 node = tree_search(tree, start);
738 prealloc = alloc_extent_state_atomic(prealloc);
740 err = insert_state(tree, prealloc, start, end, &bits);
742 BUG_ON(err == -EEXIST);
745 state = rb_entry(node, struct extent_state, rb_node);
747 last_start = state->start;
748 last_end = state->end;
751 * | ---- desired range ---- |
754 * Just lock what we found and keep going
756 if (state->start == start && state->end <= end) {
757 struct rb_node *next_node;
758 if (state->state & exclusive_bits) {
759 *failed_start = state->start;
764 set_state_bits(tree, state, &bits);
766 cache_state(state, cached_state);
767 merge_state(tree, state);
768 if (last_end == (u64)-1)
771 start = last_end + 1;
772 next_node = rb_next(&state->rb_node);
773 if (next_node && start < end && prealloc && !need_resched()) {
774 state = rb_entry(next_node, struct extent_state,
776 if (state->start == start)
783 * | ---- desired range ---- |
786 * | ------------- state -------------- |
788 * We need to split the extent we found, and may flip bits on
791 * If the extent we found extends past our
792 * range, we just split and search again. It'll get split
793 * again the next time though.
795 * If the extent we found is inside our range, we set the
798 if (state->start < start) {
799 if (state->state & exclusive_bits) {
800 *failed_start = start;
805 prealloc = alloc_extent_state_atomic(prealloc);
807 err = split_state(tree, state, prealloc, start);
808 BUG_ON(err == -EEXIST);
812 if (state->end <= end) {
813 set_state_bits(tree, state, &bits);
814 cache_state(state, cached_state);
815 merge_state(tree, state);
816 if (last_end == (u64)-1)
818 start = last_end + 1;
823 * | ---- desired range ---- |
824 * | state | or | state |
826 * There's a hole, we need to insert something in it and
827 * ignore the extent we found.
829 if (state->start > start) {
831 if (end < last_start)
834 this_end = last_start - 1;
836 prealloc = alloc_extent_state_atomic(prealloc);
840 * Avoid to free 'prealloc' if it can be merged with
843 err = insert_state(tree, prealloc, start, this_end,
845 BUG_ON(err == -EEXIST);
847 free_extent_state(prealloc);
851 cache_state(prealloc, cached_state);
853 start = this_end + 1;
857 * | ---- desired range ---- |
859 * We need to split the extent, and set the bit
862 if (state->start <= end && state->end > end) {
863 if (state->state & exclusive_bits) {
864 *failed_start = start;
869 prealloc = alloc_extent_state_atomic(prealloc);
871 err = split_state(tree, state, prealloc, end + 1);
872 BUG_ON(err == -EEXIST);
874 set_state_bits(tree, prealloc, &bits);
875 cache_state(prealloc, cached_state);
876 merge_state(tree, prealloc);
884 spin_unlock(&tree->lock);
886 free_extent_state(prealloc);
893 spin_unlock(&tree->lock);
894 if (mask & __GFP_WAIT)
900 * convert_extent - convert all bits in a given range from one bit to another
901 * @tree: the io tree to search
902 * @start: the start offset in bytes
903 * @end: the end offset in bytes (inclusive)
904 * @bits: the bits to set in this range
905 * @clear_bits: the bits to clear in this range
906 * @mask: the allocation mask
908 * This will go through and set bits for the given range. If any states exist
909 * already in this range they are set with the given bit and cleared of the
910 * clear_bits. This is only meant to be used by things that are mergeable, ie
911 * converting from say DELALLOC to DIRTY. This is not meant to be used with
912 * boundary bits like LOCK.
914 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
915 int bits, int clear_bits, gfp_t mask)
917 struct extent_state *state;
918 struct extent_state *prealloc = NULL;
919 struct rb_node *node;
925 if (!prealloc && (mask & __GFP_WAIT)) {
926 prealloc = alloc_extent_state(mask);
931 spin_lock(&tree->lock);
933 * this search will find all the extents that end after
936 node = tree_search(tree, start);
938 prealloc = alloc_extent_state_atomic(prealloc);
943 err = insert_state(tree, prealloc, start, end, &bits);
945 BUG_ON(err == -EEXIST);
948 state = rb_entry(node, struct extent_state, rb_node);
950 last_start = state->start;
951 last_end = state->end;
954 * | ---- desired range ---- |
957 * Just lock what we found and keep going
959 if (state->start == start && state->end <= end) {
960 struct rb_node *next_node;
962 set_state_bits(tree, state, &bits);
963 clear_state_bit(tree, state, &clear_bits, 0);
965 merge_state(tree, state);
966 if (last_end == (u64)-1)
969 start = last_end + 1;
970 next_node = rb_next(&state->rb_node);
971 if (next_node && start < end && prealloc && !need_resched()) {
972 state = rb_entry(next_node, struct extent_state,
974 if (state->start == start)
981 * | ---- desired range ---- |
984 * | ------------- state -------------- |
986 * We need to split the extent we found, and may flip bits on
989 * If the extent we found extends past our
990 * range, we just split and search again. It'll get split
991 * again the next time though.
993 * If the extent we found is inside our range, we set the
996 if (state->start < start) {
997 prealloc = alloc_extent_state_atomic(prealloc);
1002 err = split_state(tree, state, prealloc, start);
1003 BUG_ON(err == -EEXIST);
1007 if (state->end <= end) {
1008 set_state_bits(tree, state, &bits);
1009 clear_state_bit(tree, state, &clear_bits, 0);
1010 merge_state(tree, state);
1011 if (last_end == (u64)-1)
1013 start = last_end + 1;
1018 * | ---- desired range ---- |
1019 * | state | or | state |
1021 * There's a hole, we need to insert something in it and
1022 * ignore the extent we found.
1024 if (state->start > start) {
1026 if (end < last_start)
1029 this_end = last_start - 1;
1031 prealloc = alloc_extent_state_atomic(prealloc);
1038 * Avoid to free 'prealloc' if it can be merged with
1041 err = insert_state(tree, prealloc, start, this_end,
1043 BUG_ON(err == -EEXIST);
1045 free_extent_state(prealloc);
1050 start = this_end + 1;
1054 * | ---- desired range ---- |
1056 * We need to split the extent, and set the bit
1059 if (state->start <= end && state->end > end) {
1060 prealloc = alloc_extent_state_atomic(prealloc);
1066 err = split_state(tree, state, prealloc, end + 1);
1067 BUG_ON(err == -EEXIST);
1069 set_state_bits(tree, prealloc, &bits);
1070 clear_state_bit(tree, prealloc, &clear_bits, 0);
1072 merge_state(tree, prealloc);
1080 spin_unlock(&tree->lock);
1082 free_extent_state(prealloc);
1089 spin_unlock(&tree->lock);
1090 if (mask & __GFP_WAIT)
1095 /* wrappers around set/clear extent bit */
1096 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1099 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
1103 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1104 int bits, gfp_t mask)
1106 return set_extent_bit(tree, start, end, bits, 0, NULL,
1110 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1111 int bits, gfp_t mask)
1113 return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
1116 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
1117 struct extent_state **cached_state, gfp_t mask)
1119 return set_extent_bit(tree, start, end,
1120 EXTENT_DELALLOC | EXTENT_UPTODATE,
1121 0, NULL, cached_state, mask);
1124 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1127 return clear_extent_bit(tree, start, end,
1128 EXTENT_DIRTY | EXTENT_DELALLOC |
1129 EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
1132 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
1135 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
1139 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
1140 struct extent_state **cached_state, gfp_t mask)
1142 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0,
1143 NULL, cached_state, mask);
1146 static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
1147 u64 end, struct extent_state **cached_state,
1150 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
1151 cached_state, mask);
1155 * either insert or lock state struct between start and end use mask to tell
1156 * us if waiting is desired.
1158 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1159 int bits, struct extent_state **cached_state, gfp_t mask)
1164 err = set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
1165 EXTENT_LOCKED, &failed_start,
1166 cached_state, mask);
1167 if (err == -EEXIST && (mask & __GFP_WAIT)) {
1168 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1169 start = failed_start;
1173 WARN_ON(start > end);
1178 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
1180 return lock_extent_bits(tree, start, end, 0, NULL, mask);
1183 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
1189 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1190 &failed_start, NULL, mask);
1191 if (err == -EEXIST) {
1192 if (failed_start > start)
1193 clear_extent_bit(tree, start, failed_start - 1,
1194 EXTENT_LOCKED, 1, 0, NULL, mask);
1200 int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
1201 struct extent_state **cached, gfp_t mask)
1203 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
1207 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
1209 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
1214 * helper function to set both pages and extents in the tree writeback
1216 static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1218 unsigned long index = start >> PAGE_CACHE_SHIFT;
1219 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1222 while (index <= end_index) {
1223 page = find_get_page(tree->mapping, index);
1225 set_page_writeback(page);
1226 page_cache_release(page);
1232 /* find the first state struct with 'bits' set after 'start', and
1233 * return it. tree->lock must be held. NULL will returned if
1234 * nothing was found after 'start'
1236 struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
1237 u64 start, int bits)
1239 struct rb_node *node;
1240 struct extent_state *state;
1243 * this search will find all the extents that end after
1246 node = tree_search(tree, start);
1251 state = rb_entry(node, struct extent_state, rb_node);
1252 if (state->end >= start && (state->state & bits))
1255 node = rb_next(node);
1264 * find the first offset in the io tree with 'bits' set. zero is
1265 * returned if we find something, and *start_ret and *end_ret are
1266 * set to reflect the state struct that was found.
1268 * If nothing was found, 1 is returned, < 0 on error
1270 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1271 u64 *start_ret, u64 *end_ret, int bits)
1273 struct extent_state *state;
1276 spin_lock(&tree->lock);
1277 state = find_first_extent_bit_state(tree, start, bits);
1279 *start_ret = state->start;
1280 *end_ret = state->end;
1283 spin_unlock(&tree->lock);
1288 * find a contiguous range of bytes in the file marked as delalloc, not
1289 * more than 'max_bytes'. start and end are used to return the range,
1291 * 1 is returned if we find something, 0 if nothing was in the tree
1293 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1294 u64 *start, u64 *end, u64 max_bytes,
1295 struct extent_state **cached_state)
1297 struct rb_node *node;
1298 struct extent_state *state;
1299 u64 cur_start = *start;
1301 u64 total_bytes = 0;
1303 spin_lock(&tree->lock);
1306 * this search will find all the extents that end after
1309 node = tree_search(tree, cur_start);
1317 state = rb_entry(node, struct extent_state, rb_node);
1318 if (found && (state->start != cur_start ||
1319 (state->state & EXTENT_BOUNDARY))) {
1322 if (!(state->state & EXTENT_DELALLOC)) {
1328 *start = state->start;
1329 *cached_state = state;
1330 atomic_inc(&state->refs);
1334 cur_start = state->end + 1;
1335 node = rb_next(node);
1338 total_bytes += state->end - state->start + 1;
1339 if (total_bytes >= max_bytes)
1343 spin_unlock(&tree->lock);
1347 static noinline int __unlock_for_delalloc(struct inode *inode,
1348 struct page *locked_page,
1352 struct page *pages[16];
1353 unsigned long index = start >> PAGE_CACHE_SHIFT;
1354 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1355 unsigned long nr_pages = end_index - index + 1;
1358 if (index == locked_page->index && end_index == index)
1361 while (nr_pages > 0) {
1362 ret = find_get_pages_contig(inode->i_mapping, index,
1363 min_t(unsigned long, nr_pages,
1364 ARRAY_SIZE(pages)), pages);
1365 for (i = 0; i < ret; i++) {
1366 if (pages[i] != locked_page)
1367 unlock_page(pages[i]);
1368 page_cache_release(pages[i]);
1377 static noinline int lock_delalloc_pages(struct inode *inode,
1378 struct page *locked_page,
1382 unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
1383 unsigned long start_index = index;
1384 unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
1385 unsigned long pages_locked = 0;
1386 struct page *pages[16];
1387 unsigned long nrpages;
1391 /* the caller is responsible for locking the start index */
1392 if (index == locked_page->index && index == end_index)
1395 /* skip the page at the start index */
1396 nrpages = end_index - index + 1;
1397 while (nrpages > 0) {
1398 ret = find_get_pages_contig(inode->i_mapping, index,
1399 min_t(unsigned long,
1400 nrpages, ARRAY_SIZE(pages)), pages);
1405 /* now we have an array of pages, lock them all */
1406 for (i = 0; i < ret; i++) {
1408 * the caller is taking responsibility for
1411 if (pages[i] != locked_page) {
1412 lock_page(pages[i]);
1413 if (!PageDirty(pages[i]) ||
1414 pages[i]->mapping != inode->i_mapping) {
1416 unlock_page(pages[i]);
1417 page_cache_release(pages[i]);
1421 page_cache_release(pages[i]);
1430 if (ret && pages_locked) {
1431 __unlock_for_delalloc(inode, locked_page,
1433 ((u64)(start_index + pages_locked - 1)) <<
1440 * find a contiguous range of bytes in the file marked as delalloc, not
1441 * more than 'max_bytes'. start and end are used to return the range,
1443 * 1 is returned if we find something, 0 if nothing was in the tree
1445 static noinline u64 find_lock_delalloc_range(struct inode *inode,
1446 struct extent_io_tree *tree,
1447 struct page *locked_page,
1448 u64 *start, u64 *end,
1454 struct extent_state *cached_state = NULL;
1459 /* step one, find a bunch of delalloc bytes starting at start */
1460 delalloc_start = *start;
1462 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1463 max_bytes, &cached_state);
1464 if (!found || delalloc_end <= *start) {
1465 *start = delalloc_start;
1466 *end = delalloc_end;
1467 free_extent_state(cached_state);
1472 * start comes from the offset of locked_page. We have to lock
1473 * pages in order, so we can't process delalloc bytes before
1476 if (delalloc_start < *start)
1477 delalloc_start = *start;
1480 * make sure to limit the number of pages we try to lock down
1483 if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1484 delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
1486 /* step two, lock all the pages after the page that has start */
1487 ret = lock_delalloc_pages(inode, locked_page,
1488 delalloc_start, delalloc_end);
1489 if (ret == -EAGAIN) {
1490 /* some of the pages are gone, lets avoid looping by
1491 * shortening the size of the delalloc range we're searching
1493 free_extent_state(cached_state);
1495 unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
1496 max_bytes = PAGE_CACHE_SIZE - offset;
1506 /* step three, lock the state bits for the whole range */
1507 lock_extent_bits(tree, delalloc_start, delalloc_end,
1508 0, &cached_state, GFP_NOFS);
1510 /* then test to make sure it is all still delalloc */
1511 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1512 EXTENT_DELALLOC, 1, cached_state);
1514 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1515 &cached_state, GFP_NOFS);
1516 __unlock_for_delalloc(inode, locked_page,
1517 delalloc_start, delalloc_end);
1521 free_extent_state(cached_state);
1522 *start = delalloc_start;
1523 *end = delalloc_end;
1528 int extent_clear_unlock_delalloc(struct inode *inode,
1529 struct extent_io_tree *tree,
1530 u64 start, u64 end, struct page *locked_page,
1534 struct page *pages[16];
1535 unsigned long index = start >> PAGE_CACHE_SHIFT;
1536 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1537 unsigned long nr_pages = end_index - index + 1;
1541 if (op & EXTENT_CLEAR_UNLOCK)
1542 clear_bits |= EXTENT_LOCKED;
1543 if (op & EXTENT_CLEAR_DIRTY)
1544 clear_bits |= EXTENT_DIRTY;
1546 if (op & EXTENT_CLEAR_DELALLOC)
1547 clear_bits |= EXTENT_DELALLOC;
1549 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1550 if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
1551 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
1552 EXTENT_SET_PRIVATE2)))
1555 while (nr_pages > 0) {
1556 ret = find_get_pages_contig(inode->i_mapping, index,
1557 min_t(unsigned long,
1558 nr_pages, ARRAY_SIZE(pages)), pages);
1559 for (i = 0; i < ret; i++) {
1561 if (op & EXTENT_SET_PRIVATE2)
1562 SetPagePrivate2(pages[i]);
1564 if (pages[i] == locked_page) {
1565 page_cache_release(pages[i]);
1568 if (op & EXTENT_CLEAR_DIRTY)
1569 clear_page_dirty_for_io(pages[i]);
1570 if (op & EXTENT_SET_WRITEBACK)
1571 set_page_writeback(pages[i]);
1572 if (op & EXTENT_END_WRITEBACK)
1573 end_page_writeback(pages[i]);
1574 if (op & EXTENT_CLEAR_UNLOCK_PAGE)
1575 unlock_page(pages[i]);
1576 page_cache_release(pages[i]);
1586 * count the number of bytes in the tree that have a given bit(s)
1587 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1588 * cached. The total number found is returned.
1590 u64 count_range_bits(struct extent_io_tree *tree,
1591 u64 *start, u64 search_end, u64 max_bytes,
1592 unsigned long bits, int contig)
1594 struct rb_node *node;
1595 struct extent_state *state;
1596 u64 cur_start = *start;
1597 u64 total_bytes = 0;
1601 if (search_end <= cur_start) {
1606 spin_lock(&tree->lock);
1607 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1608 total_bytes = tree->dirty_bytes;
1612 * this search will find all the extents that end after
1615 node = tree_search(tree, cur_start);
1620 state = rb_entry(node, struct extent_state, rb_node);
1621 if (state->start > search_end)
1623 if (contig && found && state->start > last + 1)
1625 if (state->end >= cur_start && (state->state & bits) == bits) {
1626 total_bytes += min(search_end, state->end) + 1 -
1627 max(cur_start, state->start);
1628 if (total_bytes >= max_bytes)
1631 *start = max(cur_start, state->start);
1635 } else if (contig && found) {
1638 node = rb_next(node);
1643 spin_unlock(&tree->lock);
1648 * set the private field for a given byte offset in the tree. If there isn't
1649 * an extent_state there already, this does nothing.
1651 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1653 struct rb_node *node;
1654 struct extent_state *state;
1657 spin_lock(&tree->lock);
1659 * this search will find all the extents that end after
1662 node = tree_search(tree, start);
1667 state = rb_entry(node, struct extent_state, rb_node);
1668 if (state->start != start) {
1672 state->private = private;
1674 spin_unlock(&tree->lock);
1678 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1680 struct rb_node *node;
1681 struct extent_state *state;
1684 spin_lock(&tree->lock);
1686 * this search will find all the extents that end after
1689 node = tree_search(tree, start);
1694 state = rb_entry(node, struct extent_state, rb_node);
1695 if (state->start != start) {
1699 *private = state->private;
1701 spin_unlock(&tree->lock);
1706 * searches a range in the state tree for a given mask.
1707 * If 'filled' == 1, this returns 1 only if every extent in the tree
1708 * has the bits set. Otherwise, 1 is returned if any bit in the
1709 * range is found set.
1711 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1712 int bits, int filled, struct extent_state *cached)
1714 struct extent_state *state = NULL;
1715 struct rb_node *node;
1718 spin_lock(&tree->lock);
1719 if (cached && cached->tree && cached->start <= start &&
1720 cached->end > start)
1721 node = &cached->rb_node;
1723 node = tree_search(tree, start);
1724 while (node && start <= end) {
1725 state = rb_entry(node, struct extent_state, rb_node);
1727 if (filled && state->start > start) {
1732 if (state->start > end)
1735 if (state->state & bits) {
1739 } else if (filled) {
1744 if (state->end == (u64)-1)
1747 start = state->end + 1;
1750 node = rb_next(node);
1757 spin_unlock(&tree->lock);
1762 * helper function to set a given page up to date if all the
1763 * extents in the tree for that page are up to date
1765 static int check_page_uptodate(struct extent_io_tree *tree,
1768 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1769 u64 end = start + PAGE_CACHE_SIZE - 1;
1770 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1771 SetPageUptodate(page);
1776 * helper function to unlock a page if all the extents in the tree
1777 * for that page are unlocked
1779 static int check_page_locked(struct extent_io_tree *tree,
1782 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1783 u64 end = start + PAGE_CACHE_SIZE - 1;
1784 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
1790 * helper function to end page writeback if all the extents
1791 * in the tree for that page are done with writeback
1793 static int check_page_writeback(struct extent_io_tree *tree,
1796 end_page_writeback(page);
1801 * When IO fails, either with EIO or csum verification fails, we
1802 * try other mirrors that might have a good copy of the data. This
1803 * io_failure_record is used to record state as we go through all the
1804 * mirrors. If another mirror has good data, the page is set up to date
1805 * and things continue. If a good mirror can't be found, the original
1806 * bio end_io callback is called to indicate things have failed.
1808 struct io_failure_record {
1813 unsigned long bio_flags;
1819 static int free_io_failure(struct inode *inode, struct io_failure_record *rec,
1824 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1826 set_state_private(failure_tree, rec->start, 0);
1827 ret = clear_extent_bits(failure_tree, rec->start,
1828 rec->start + rec->len - 1,
1829 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
1834 ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
1835 rec->start + rec->len - 1,
1836 EXTENT_DAMAGED, GFP_NOFS);
1845 static void repair_io_failure_callback(struct bio *bio, int err)
1847 complete(bio->bi_private);
1851 * this bypasses the standard btrfs submit functions deliberately, as
1852 * the standard behavior is to write all copies in a raid setup. here we only
1853 * want to write the one bad copy. so we do the mapping for ourselves and issue
1854 * submit_bio directly.
1855 * to avoid any synchonization issues, wait for the data after writing, which
1856 * actually prevents the read that triggered the error from finishing.
1857 * currently, there can be no more than two copies of every data bit. thus,
1858 * exactly one rewrite is required.
1860 int repair_io_failure(struct btrfs_mapping_tree *map_tree, u64 start,
1861 u64 length, u64 logical, struct page *page,
1865 struct btrfs_device *dev;
1866 DECLARE_COMPLETION_ONSTACK(compl);
1869 struct btrfs_bio *bbio = NULL;
1872 BUG_ON(!mirror_num);
1874 bio = bio_alloc(GFP_NOFS, 1);
1877 bio->bi_private = &compl;
1878 bio->bi_end_io = repair_io_failure_callback;
1880 map_length = length;
1882 ret = btrfs_map_block(map_tree, WRITE, logical,
1883 &map_length, &bbio, mirror_num);
1888 BUG_ON(mirror_num != bbio->mirror_num);
1889 sector = bbio->stripes[mirror_num-1].physical >> 9;
1890 bio->bi_sector = sector;
1891 dev = bbio->stripes[mirror_num-1].dev;
1893 if (!dev || !dev->bdev || !dev->writeable) {
1897 bio->bi_bdev = dev->bdev;
1898 bio_add_page(bio, page, length, start-page_offset(page));
1899 btrfsic_submit_bio(WRITE_SYNC, bio);
1900 wait_for_completion(&compl);
1902 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
1903 /* try to remap that extent elsewhere? */
1908 printk(KERN_INFO "btrfs read error corrected: ino %lu off %llu (dev %s "
1909 "sector %llu)\n", page->mapping->host->i_ino, start,
1917 * each time an IO finishes, we do a fast check in the IO failure tree
1918 * to see if we need to process or clean up an io_failure_record
1920 static int clean_io_failure(u64 start, struct page *page)
1923 u64 private_failure;
1924 struct io_failure_record *failrec;
1925 struct btrfs_mapping_tree *map_tree;
1926 struct extent_state *state;
1930 struct inode *inode = page->mapping->host;
1933 ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
1934 (u64)-1, 1, EXTENT_DIRTY, 0);
1938 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree, start,
1943 failrec = (struct io_failure_record *)(unsigned long) private_failure;
1944 BUG_ON(!failrec->this_mirror);
1946 if (failrec->in_validation) {
1947 /* there was no real error, just free the record */
1948 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
1954 spin_lock(&BTRFS_I(inode)->io_tree.lock);
1955 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
1958 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
1960 if (state && state->start == failrec->start) {
1961 map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree;
1962 num_copies = btrfs_num_copies(map_tree, failrec->logical,
1964 if (num_copies > 1) {
1965 ret = repair_io_failure(map_tree, start, failrec->len,
1966 failrec->logical, page,
1967 failrec->failed_mirror);
1974 ret = free_io_failure(inode, failrec, did_repair);
1980 * this is a generic handler for readpage errors (default
1981 * readpage_io_failed_hook). if other copies exist, read those and write back
1982 * good data to the failed position. does not investigate in remapping the
1983 * failed extent elsewhere, hoping the device will be smart enough to do this as
1987 static int bio_readpage_error(struct bio *failed_bio, struct page *page,
1988 u64 start, u64 end, int failed_mirror,
1989 struct extent_state *state)
1991 struct io_failure_record *failrec = NULL;
1993 struct extent_map *em;
1994 struct inode *inode = page->mapping->host;
1995 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1996 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
1997 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2004 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
2006 ret = get_state_private(failure_tree, start, &private);
2008 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2011 failrec->start = start;
2012 failrec->len = end - start + 1;
2013 failrec->this_mirror = 0;
2014 failrec->bio_flags = 0;
2015 failrec->in_validation = 0;
2017 read_lock(&em_tree->lock);
2018 em = lookup_extent_mapping(em_tree, start, failrec->len);
2020 read_unlock(&em_tree->lock);
2025 if (em->start > start || em->start + em->len < start) {
2026 free_extent_map(em);
2029 read_unlock(&em_tree->lock);
2031 if (!em || IS_ERR(em)) {
2035 logical = start - em->start;
2036 logical = em->block_start + logical;
2037 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2038 logical = em->block_start;
2039 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2040 extent_set_compress_type(&failrec->bio_flags,
2043 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2044 "len=%llu\n", logical, start, failrec->len);
2045 failrec->logical = logical;
2046 free_extent_map(em);
2048 /* set the bits in the private failure tree */
2049 ret = set_extent_bits(failure_tree, start, end,
2050 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
2052 ret = set_state_private(failure_tree, start,
2053 (u64)(unsigned long)failrec);
2054 /* set the bits in the inode's tree */
2056 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED,
2063 failrec = (struct io_failure_record *)(unsigned long)private;
2064 pr_debug("bio_readpage_error: (found) logical=%llu, "
2065 "start=%llu, len=%llu, validation=%d\n",
2066 failrec->logical, failrec->start, failrec->len,
2067 failrec->in_validation);
2069 * when data can be on disk more than twice, add to failrec here
2070 * (e.g. with a list for failed_mirror) to make
2071 * clean_io_failure() clean all those errors at once.
2074 num_copies = btrfs_num_copies(
2075 &BTRFS_I(inode)->root->fs_info->mapping_tree,
2076 failrec->logical, failrec->len);
2077 if (num_copies == 1) {
2079 * we only have a single copy of the data, so don't bother with
2080 * all the retry and error correction code that follows. no
2081 * matter what the error is, it is very likely to persist.
2083 pr_debug("bio_readpage_error: cannot repair, num_copies == 1. "
2084 "state=%p, num_copies=%d, next_mirror %d, "
2085 "failed_mirror %d\n", state, num_copies,
2086 failrec->this_mirror, failed_mirror);
2087 free_io_failure(inode, failrec, 0);
2092 spin_lock(&tree->lock);
2093 state = find_first_extent_bit_state(tree, failrec->start,
2095 if (state && state->start != failrec->start)
2097 spin_unlock(&tree->lock);
2101 * there are two premises:
2102 * a) deliver good data to the caller
2103 * b) correct the bad sectors on disk
2105 if (failed_bio->bi_vcnt > 1) {
2107 * to fulfill b), we need to know the exact failing sectors, as
2108 * we don't want to rewrite any more than the failed ones. thus,
2109 * we need separate read requests for the failed bio
2111 * if the following BUG_ON triggers, our validation request got
2112 * merged. we need separate requests for our algorithm to work.
2114 BUG_ON(failrec->in_validation);
2115 failrec->in_validation = 1;
2116 failrec->this_mirror = failed_mirror;
2117 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
2120 * we're ready to fulfill a) and b) alongside. get a good copy
2121 * of the failed sector and if we succeed, we have setup
2122 * everything for repair_io_failure to do the rest for us.
2124 if (failrec->in_validation) {
2125 BUG_ON(failrec->this_mirror != failed_mirror);
2126 failrec->in_validation = 0;
2127 failrec->this_mirror = 0;
2129 failrec->failed_mirror = failed_mirror;
2130 failrec->this_mirror++;
2131 if (failrec->this_mirror == failed_mirror)
2132 failrec->this_mirror++;
2133 read_mode = READ_SYNC;
2136 if (!state || failrec->this_mirror > num_copies) {
2137 pr_debug("bio_readpage_error: (fail) state=%p, num_copies=%d, "
2138 "next_mirror %d, failed_mirror %d\n", state,
2139 num_copies, failrec->this_mirror, failed_mirror);
2140 free_io_failure(inode, failrec, 0);
2144 bio = bio_alloc(GFP_NOFS, 1);
2145 bio->bi_private = state;
2146 bio->bi_end_io = failed_bio->bi_end_io;
2147 bio->bi_sector = failrec->logical >> 9;
2148 bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
2151 bio_add_page(bio, page, failrec->len, start - page_offset(page));
2153 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2154 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode,
2155 failrec->this_mirror, num_copies, failrec->in_validation);
2157 tree->ops->submit_bio_hook(inode, read_mode, bio, failrec->this_mirror,
2158 failrec->bio_flags, 0);
2162 /* lots and lots of room for performance fixes in the end_bio funcs */
2165 * after a writepage IO is done, we need to:
2166 * clear the uptodate bits on error
2167 * clear the writeback bits in the extent tree for this IO
2168 * end_page_writeback if the page has no more pending IO
2170 * Scheduling is not allowed, so the extent state tree is expected
2171 * to have one and only one object corresponding to this IO.
2173 static void end_bio_extent_writepage(struct bio *bio, int err)
2175 int uptodate = err == 0;
2176 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2177 struct extent_io_tree *tree;
2184 struct page *page = bvec->bv_page;
2185 tree = &BTRFS_I(page->mapping->host)->io_tree;
2187 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
2189 end = start + bvec->bv_len - 1;
2191 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
2196 if (--bvec >= bio->bi_io_vec)
2197 prefetchw(&bvec->bv_page->flags);
2198 if (tree->ops && tree->ops->writepage_end_io_hook) {
2199 ret = tree->ops->writepage_end_io_hook(page, start,
2200 end, NULL, uptodate);
2205 if (!uptodate && tree->ops &&
2206 tree->ops->writepage_io_failed_hook) {
2207 ret = tree->ops->writepage_io_failed_hook(bio, page,
2210 uptodate = (err == 0);
2216 clear_extent_uptodate(tree, start, end, NULL, GFP_NOFS);
2217 ClearPageUptodate(page);
2222 end_page_writeback(page);
2224 check_page_writeback(tree, page);
2225 } while (bvec >= bio->bi_io_vec);
2231 * after a readpage IO is done, we need to:
2232 * clear the uptodate bits on error
2233 * set the uptodate bits if things worked
2234 * set the page up to date if all extents in the tree are uptodate
2235 * clear the lock bit in the extent tree
2236 * unlock the page if there are no other extents locked for it
2238 * Scheduling is not allowed, so the extent state tree is expected
2239 * to have one and only one object corresponding to this IO.
2241 static void end_bio_extent_readpage(struct bio *bio, int err)
2243 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
2244 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
2245 struct bio_vec *bvec = bio->bi_io_vec;
2246 struct extent_io_tree *tree;
2256 struct page *page = bvec->bv_page;
2257 struct extent_state *cached = NULL;
2258 struct extent_state *state;
2260 pr_debug("end_bio_extent_readpage: bi_vcnt=%d, idx=%d, err=%d, "
2261 "mirror=%ld\n", bio->bi_vcnt, bio->bi_idx, err,
2262 (long int)bio->bi_bdev);
2263 tree = &BTRFS_I(page->mapping->host)->io_tree;
2265 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
2267 end = start + bvec->bv_len - 1;
2269 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
2274 if (++bvec <= bvec_end)
2275 prefetchw(&bvec->bv_page->flags);
2277 spin_lock(&tree->lock);
2278 state = find_first_extent_bit_state(tree, start, EXTENT_LOCKED);
2279 if (state && state->start == start) {
2281 * take a reference on the state, unlock will drop
2284 cache_state(state, &cached);
2286 spin_unlock(&tree->lock);
2288 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
2289 ret = tree->ops->readpage_end_io_hook(page, start, end,
2294 clean_io_failure(start, page);
2298 failed_mirror = (int)(unsigned long)bio->bi_bdev;
2300 * The generic bio_readpage_error handles errors the
2301 * following way: If possible, new read requests are
2302 * created and submitted and will end up in
2303 * end_bio_extent_readpage as well (if we're lucky, not
2304 * in the !uptodate case). In that case it returns 0 and
2305 * we just go on with the next page in our bio. If it
2306 * can't handle the error it will return -EIO and we
2307 * remain responsible for that page.
2309 ret = bio_readpage_error(bio, page, start, end,
2310 failed_mirror, NULL);
2314 test_bit(BIO_UPTODATE, &bio->bi_flags);
2317 uncache_state(&cached);
2320 if (tree->ops && tree->ops->readpage_io_failed_hook) {
2321 ret = tree->ops->readpage_io_failed_hook(
2322 bio, page, start, end,
2323 failed_mirror, state);
2330 set_extent_uptodate(tree, start, end, &cached,
2333 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2337 SetPageUptodate(page);
2339 ClearPageUptodate(page);
2345 check_page_uptodate(tree, page);
2347 ClearPageUptodate(page);
2350 check_page_locked(tree, page);
2352 } while (bvec <= bvec_end);
2358 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2363 bio = bio_alloc(gfp_flags, nr_vecs);
2365 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2366 while (!bio && (nr_vecs /= 2))
2367 bio = bio_alloc(gfp_flags, nr_vecs);
2372 bio->bi_bdev = bdev;
2373 bio->bi_sector = first_sector;
2378 static int submit_one_bio(int rw, struct bio *bio, int mirror_num,
2379 unsigned long bio_flags)
2382 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2383 struct page *page = bvec->bv_page;
2384 struct extent_io_tree *tree = bio->bi_private;
2387 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
2389 bio->bi_private = NULL;
2393 if (tree->ops && tree->ops->submit_bio_hook)
2394 ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
2395 mirror_num, bio_flags, start);
2397 btrfsic_submit_bio(rw, bio);
2399 if (bio_flagged(bio, BIO_EOPNOTSUPP))
2405 static int submit_extent_page(int rw, struct extent_io_tree *tree,
2406 struct page *page, sector_t sector,
2407 size_t size, unsigned long offset,
2408 struct block_device *bdev,
2409 struct bio **bio_ret,
2410 unsigned long max_pages,
2411 bio_end_io_t end_io_func,
2413 unsigned long prev_bio_flags,
2414 unsigned long bio_flags)
2420 int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
2421 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2422 size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
2424 if (bio_ret && *bio_ret) {
2427 contig = bio->bi_sector == sector;
2429 contig = bio->bi_sector + (bio->bi_size >> 9) ==
2432 if (prev_bio_flags != bio_flags || !contig ||
2433 (tree->ops && tree->ops->merge_bio_hook &&
2434 tree->ops->merge_bio_hook(page, offset, page_size, bio,
2436 bio_add_page(bio, page, page_size, offset) < page_size) {
2437 ret = submit_one_bio(rw, bio, mirror_num,
2444 if (this_compressed)
2447 nr = bio_get_nr_vecs(bdev);
2449 bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
2453 bio_add_page(bio, page, page_size, offset);
2454 bio->bi_end_io = end_io_func;
2455 bio->bi_private = tree;
2460 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
2465 void set_page_extent_mapped(struct page *page)
2467 if (!PagePrivate(page)) {
2468 SetPagePrivate(page);
2469 page_cache_get(page);
2470 set_page_private(page, EXTENT_PAGE_PRIVATE);
2474 static void set_page_extent_head(struct page *page, unsigned long len)
2476 WARN_ON(!PagePrivate(page));
2477 set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
2481 * basic readpage implementation. Locked extent state structs are inserted
2482 * into the tree that are removed when the IO is done (by the end_io
2485 static int __extent_read_full_page(struct extent_io_tree *tree,
2487 get_extent_t *get_extent,
2488 struct bio **bio, int mirror_num,
2489 unsigned long *bio_flags)
2491 struct inode *inode = page->mapping->host;
2492 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2493 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2497 u64 last_byte = i_size_read(inode);
2501 struct extent_map *em;
2502 struct block_device *bdev;
2503 struct btrfs_ordered_extent *ordered;
2506 size_t pg_offset = 0;
2508 size_t disk_io_size;
2509 size_t blocksize = inode->i_sb->s_blocksize;
2510 unsigned long this_bio_flag = 0;
2512 set_page_extent_mapped(page);
2514 if (!PageUptodate(page)) {
2515 if (cleancache_get_page(page) == 0) {
2516 BUG_ON(blocksize != PAGE_SIZE);
2523 lock_extent(tree, start, end, GFP_NOFS);
2524 ordered = btrfs_lookup_ordered_extent(inode, start);
2527 unlock_extent(tree, start, end, GFP_NOFS);
2528 btrfs_start_ordered_extent(inode, ordered, 1);
2529 btrfs_put_ordered_extent(ordered);
2532 if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
2534 size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
2537 iosize = PAGE_CACHE_SIZE - zero_offset;
2538 userpage = kmap_atomic(page, KM_USER0);
2539 memset(userpage + zero_offset, 0, iosize);
2540 flush_dcache_page(page);
2541 kunmap_atomic(userpage, KM_USER0);
2544 while (cur <= end) {
2545 if (cur >= last_byte) {
2547 struct extent_state *cached = NULL;
2549 iosize = PAGE_CACHE_SIZE - pg_offset;
2550 userpage = kmap_atomic(page, KM_USER0);
2551 memset(userpage + pg_offset, 0, iosize);
2552 flush_dcache_page(page);
2553 kunmap_atomic(userpage, KM_USER0);
2554 set_extent_uptodate(tree, cur, cur + iosize - 1,
2556 unlock_extent_cached(tree, cur, cur + iosize - 1,
2560 em = get_extent(inode, page, pg_offset, cur,
2562 if (IS_ERR_OR_NULL(em)) {
2564 unlock_extent(tree, cur, end, GFP_NOFS);
2567 extent_offset = cur - em->start;
2568 BUG_ON(extent_map_end(em) <= cur);
2571 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2572 this_bio_flag = EXTENT_BIO_COMPRESSED;
2573 extent_set_compress_type(&this_bio_flag,
2577 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2578 cur_end = min(extent_map_end(em) - 1, end);
2579 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2580 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2581 disk_io_size = em->block_len;
2582 sector = em->block_start >> 9;
2584 sector = (em->block_start + extent_offset) >> 9;
2585 disk_io_size = iosize;
2588 block_start = em->block_start;
2589 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2590 block_start = EXTENT_MAP_HOLE;
2591 free_extent_map(em);
2594 /* we've found a hole, just zero and go on */
2595 if (block_start == EXTENT_MAP_HOLE) {
2597 struct extent_state *cached = NULL;
2599 userpage = kmap_atomic(page, KM_USER0);
2600 memset(userpage + pg_offset, 0, iosize);
2601 flush_dcache_page(page);
2602 kunmap_atomic(userpage, KM_USER0);
2604 set_extent_uptodate(tree, cur, cur + iosize - 1,
2606 unlock_extent_cached(tree, cur, cur + iosize - 1,
2609 pg_offset += iosize;
2612 /* the get_extent function already copied into the page */
2613 if (test_range_bit(tree, cur, cur_end,
2614 EXTENT_UPTODATE, 1, NULL)) {
2615 check_page_uptodate(tree, page);
2616 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2618 pg_offset += iosize;
2621 /* we have an inline extent but it didn't get marked up
2622 * to date. Error out
2624 if (block_start == EXTENT_MAP_INLINE) {
2626 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2628 pg_offset += iosize;
2633 if (tree->ops && tree->ops->readpage_io_hook) {
2634 ret = tree->ops->readpage_io_hook(page, cur,
2638 unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
2640 ret = submit_extent_page(READ, tree, page,
2641 sector, disk_io_size, pg_offset,
2643 end_bio_extent_readpage, mirror_num,
2647 *bio_flags = this_bio_flag;
2652 pg_offset += iosize;
2656 if (!PageError(page))
2657 SetPageUptodate(page);
2663 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
2664 get_extent_t *get_extent, int mirror_num)
2666 struct bio *bio = NULL;
2667 unsigned long bio_flags = 0;
2670 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
2673 ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
2677 static noinline void update_nr_written(struct page *page,
2678 struct writeback_control *wbc,
2679 unsigned long nr_written)
2681 wbc->nr_to_write -= nr_written;
2682 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
2683 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
2684 page->mapping->writeback_index = page->index + nr_written;
2688 * the writepage semantics are similar to regular writepage. extent
2689 * records are inserted to lock ranges in the tree, and as dirty areas
2690 * are found, they are marked writeback. Then the lock bits are removed
2691 * and the end_io handler clears the writeback ranges
2693 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
2696 struct inode *inode = page->mapping->host;
2697 struct extent_page_data *epd = data;
2698 struct extent_io_tree *tree = epd->tree;
2699 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2701 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2705 u64 last_byte = i_size_read(inode);
2709 struct extent_state *cached_state = NULL;
2710 struct extent_map *em;
2711 struct block_device *bdev;
2714 size_t pg_offset = 0;
2716 loff_t i_size = i_size_read(inode);
2717 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
2723 unsigned long nr_written = 0;
2724 bool fill_delalloc = true;
2726 if (wbc->sync_mode == WB_SYNC_ALL)
2727 write_flags = WRITE_SYNC;
2729 write_flags = WRITE;
2731 trace___extent_writepage(page, inode, wbc);
2733 WARN_ON(!PageLocked(page));
2735 ClearPageError(page);
2737 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2738 if (page->index > end_index ||
2739 (page->index == end_index && !pg_offset)) {
2740 page->mapping->a_ops->invalidatepage(page, 0);
2745 if (page->index == end_index) {
2748 userpage = kmap_atomic(page, KM_USER0);
2749 memset(userpage + pg_offset, 0,
2750 PAGE_CACHE_SIZE - pg_offset);
2751 kunmap_atomic(userpage, KM_USER0);
2752 flush_dcache_page(page);
2756 set_page_extent_mapped(page);
2758 if (!tree->ops || !tree->ops->fill_delalloc)
2759 fill_delalloc = false;
2761 delalloc_start = start;
2764 if (!epd->extent_locked && fill_delalloc) {
2765 u64 delalloc_to_write = 0;
2767 * make sure the wbc mapping index is at least updated
2770 update_nr_written(page, wbc, 0);
2772 while (delalloc_end < page_end) {
2773 nr_delalloc = find_lock_delalloc_range(inode, tree,
2778 if (nr_delalloc == 0) {
2779 delalloc_start = delalloc_end + 1;
2782 tree->ops->fill_delalloc(inode, page, delalloc_start,
2783 delalloc_end, &page_started,
2786 * delalloc_end is already one less than the total
2787 * length, so we don't subtract one from
2790 delalloc_to_write += (delalloc_end - delalloc_start +
2793 delalloc_start = delalloc_end + 1;
2795 if (wbc->nr_to_write < delalloc_to_write) {
2798 if (delalloc_to_write < thresh * 2)
2799 thresh = delalloc_to_write;
2800 wbc->nr_to_write = min_t(u64, delalloc_to_write,
2804 /* did the fill delalloc function already unlock and start
2810 * we've unlocked the page, so we can't update
2811 * the mapping's writeback index, just update
2814 wbc->nr_to_write -= nr_written;
2818 if (tree->ops && tree->ops->writepage_start_hook) {
2819 ret = tree->ops->writepage_start_hook(page, start,
2821 if (ret == -EAGAIN) {
2822 redirty_page_for_writepage(wbc, page);
2823 update_nr_written(page, wbc, nr_written);
2831 * we don't want to touch the inode after unlocking the page,
2832 * so we update the mapping writeback index now
2834 update_nr_written(page, wbc, nr_written + 1);
2837 if (last_byte <= start) {
2838 if (tree->ops && tree->ops->writepage_end_io_hook)
2839 tree->ops->writepage_end_io_hook(page, start,
2844 blocksize = inode->i_sb->s_blocksize;
2846 while (cur <= end) {
2847 if (cur >= last_byte) {
2848 if (tree->ops && tree->ops->writepage_end_io_hook)
2849 tree->ops->writepage_end_io_hook(page, cur,
2853 em = epd->get_extent(inode, page, pg_offset, cur,
2855 if (IS_ERR_OR_NULL(em)) {
2860 extent_offset = cur - em->start;
2861 BUG_ON(extent_map_end(em) <= cur);
2863 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2864 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2865 sector = (em->block_start + extent_offset) >> 9;
2867 block_start = em->block_start;
2868 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
2869 free_extent_map(em);
2873 * compressed and inline extents are written through other
2876 if (compressed || block_start == EXTENT_MAP_HOLE ||
2877 block_start == EXTENT_MAP_INLINE) {
2879 * end_io notification does not happen here for
2880 * compressed extents
2882 if (!compressed && tree->ops &&
2883 tree->ops->writepage_end_io_hook)
2884 tree->ops->writepage_end_io_hook(page, cur,
2887 else if (compressed) {
2888 /* we don't want to end_page_writeback on
2889 * a compressed extent. this happens
2896 pg_offset += iosize;
2899 /* leave this out until we have a page_mkwrite call */
2900 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
2901 EXTENT_DIRTY, 0, NULL)) {
2903 pg_offset += iosize;
2907 if (tree->ops && tree->ops->writepage_io_hook) {
2908 ret = tree->ops->writepage_io_hook(page, cur,
2916 unsigned long max_nr = end_index + 1;
2918 set_range_writeback(tree, cur, cur + iosize - 1);
2919 if (!PageWriteback(page)) {
2920 printk(KERN_ERR "btrfs warning page %lu not "
2921 "writeback, cur %llu end %llu\n",
2922 page->index, (unsigned long long)cur,
2923 (unsigned long long)end);
2926 ret = submit_extent_page(write_flags, tree, page,
2927 sector, iosize, pg_offset,
2928 bdev, &epd->bio, max_nr,
2929 end_bio_extent_writepage,
2935 pg_offset += iosize;
2940 /* make sure the mapping tag for page dirty gets cleared */
2941 set_page_writeback(page);
2942 end_page_writeback(page);
2948 /* drop our reference on any cached states */
2949 free_extent_state(cached_state);
2954 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2955 * @mapping: address space structure to write
2956 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2957 * @writepage: function called for each page
2958 * @data: data passed to writepage function
2960 * If a page is already under I/O, write_cache_pages() skips it, even
2961 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2962 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2963 * and msync() need to guarantee that all the data which was dirty at the time
2964 * the call was made get new I/O started against them. If wbc->sync_mode is
2965 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2966 * existing IO to complete.
2968 static int extent_write_cache_pages(struct extent_io_tree *tree,
2969 struct address_space *mapping,
2970 struct writeback_control *wbc,
2971 writepage_t writepage, void *data,
2972 void (*flush_fn)(void *))
2976 int nr_to_write_done = 0;
2977 struct pagevec pvec;
2980 pgoff_t end; /* Inclusive */
2984 pagevec_init(&pvec, 0);
2985 if (wbc->range_cyclic) {
2986 index = mapping->writeback_index; /* Start from prev offset */
2989 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2990 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2993 if (wbc->sync_mode == WB_SYNC_ALL)
2994 tag = PAGECACHE_TAG_TOWRITE;
2996 tag = PAGECACHE_TAG_DIRTY;
2998 if (wbc->sync_mode == WB_SYNC_ALL)
2999 tag_pages_for_writeback(mapping, index, end);
3000 while (!done && !nr_to_write_done && (index <= end) &&
3001 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3002 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3006 for (i = 0; i < nr_pages; i++) {
3007 struct page *page = pvec.pages[i];
3010 * At this point we hold neither mapping->tree_lock nor
3011 * lock on the page itself: the page may be truncated or
3012 * invalidated (changing page->mapping to NULL), or even
3013 * swizzled back from swapper_space to tmpfs file
3017 tree->ops->write_cache_pages_lock_hook) {
3018 tree->ops->write_cache_pages_lock_hook(page,
3021 if (!trylock_page(page)) {
3027 if (unlikely(page->mapping != mapping)) {
3032 if (!wbc->range_cyclic && page->index > end) {
3038 if (wbc->sync_mode != WB_SYNC_NONE) {
3039 if (PageWriteback(page))
3041 wait_on_page_writeback(page);
3044 if (PageWriteback(page) ||
3045 !clear_page_dirty_for_io(page)) {
3050 ret = (*writepage)(page, wbc, data);
3052 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
3060 * the filesystem may choose to bump up nr_to_write.
3061 * We have to make sure to honor the new nr_to_write
3064 nr_to_write_done = wbc->nr_to_write <= 0;
3066 pagevec_release(&pvec);
3069 if (!scanned && !done) {
3071 * We hit the last page and there is more work to be done: wrap
3072 * back to the start of the file
3081 static void flush_epd_write_bio(struct extent_page_data *epd)
3085 submit_one_bio(WRITE_SYNC, epd->bio, 0, 0);
3087 submit_one_bio(WRITE, epd->bio, 0, 0);
3092 static noinline void flush_write_bio(void *data)
3094 struct extent_page_data *epd = data;
3095 flush_epd_write_bio(epd);
3098 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
3099 get_extent_t *get_extent,
3100 struct writeback_control *wbc)
3103 struct extent_page_data epd = {
3106 .get_extent = get_extent,
3108 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3111 ret = __extent_writepage(page, wbc, &epd);
3113 flush_epd_write_bio(&epd);
3117 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
3118 u64 start, u64 end, get_extent_t *get_extent,
3122 struct address_space *mapping = inode->i_mapping;
3124 unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
3127 struct extent_page_data epd = {
3130 .get_extent = get_extent,
3132 .sync_io = mode == WB_SYNC_ALL,
3134 struct writeback_control wbc_writepages = {
3136 .nr_to_write = nr_pages * 2,
3137 .range_start = start,
3138 .range_end = end + 1,
3141 while (start <= end) {
3142 page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
3143 if (clear_page_dirty_for_io(page))
3144 ret = __extent_writepage(page, &wbc_writepages, &epd);
3146 if (tree->ops && tree->ops->writepage_end_io_hook)
3147 tree->ops->writepage_end_io_hook(page, start,
3148 start + PAGE_CACHE_SIZE - 1,
3152 page_cache_release(page);
3153 start += PAGE_CACHE_SIZE;
3156 flush_epd_write_bio(&epd);
3160 int extent_writepages(struct extent_io_tree *tree,
3161 struct address_space *mapping,
3162 get_extent_t *get_extent,
3163 struct writeback_control *wbc)
3166 struct extent_page_data epd = {
3169 .get_extent = get_extent,
3171 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3174 ret = extent_write_cache_pages(tree, mapping, wbc,
3175 __extent_writepage, &epd,
3177 flush_epd_write_bio(&epd);
3181 int extent_readpages(struct extent_io_tree *tree,
3182 struct address_space *mapping,
3183 struct list_head *pages, unsigned nr_pages,
3184 get_extent_t get_extent)
3186 struct bio *bio = NULL;
3188 unsigned long bio_flags = 0;
3190 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
3191 struct page *page = list_entry(pages->prev, struct page, lru);
3193 prefetchw(&page->flags);
3194 list_del(&page->lru);
3195 if (!add_to_page_cache_lru(page, mapping,
3196 page->index, GFP_NOFS)) {
3197 __extent_read_full_page(tree, page, get_extent,
3198 &bio, 0, &bio_flags);
3200 page_cache_release(page);
3202 BUG_ON(!list_empty(pages));
3204 submit_one_bio(READ, bio, 0, bio_flags);
3209 * basic invalidatepage code, this waits on any locked or writeback
3210 * ranges corresponding to the page, and then deletes any extent state
3211 * records from the tree
3213 int extent_invalidatepage(struct extent_io_tree *tree,
3214 struct page *page, unsigned long offset)
3216 struct extent_state *cached_state = NULL;
3217 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
3218 u64 end = start + PAGE_CACHE_SIZE - 1;
3219 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
3221 start += (offset + blocksize - 1) & ~(blocksize - 1);
3225 lock_extent_bits(tree, start, end, 0, &cached_state, GFP_NOFS);
3226 wait_on_page_writeback(page);
3227 clear_extent_bit(tree, start, end,
3228 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
3229 EXTENT_DO_ACCOUNTING,
3230 1, 1, &cached_state, GFP_NOFS);
3235 * a helper for releasepage, this tests for areas of the page that
3236 * are locked or under IO and drops the related state bits if it is safe
3239 int try_release_extent_state(struct extent_map_tree *map,
3240 struct extent_io_tree *tree, struct page *page,
3243 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
3244 u64 end = start + PAGE_CACHE_SIZE - 1;
3247 if (test_range_bit(tree, start, end,
3248 EXTENT_IOBITS, 0, NULL))
3251 if ((mask & GFP_NOFS) == GFP_NOFS)
3254 * at this point we can safely clear everything except the
3255 * locked bit and the nodatasum bit
3257 ret = clear_extent_bit(tree, start, end,
3258 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
3261 /* if clear_extent_bit failed for enomem reasons,
3262 * we can't allow the release to continue.
3273 * a helper for releasepage. As long as there are no locked extents
3274 * in the range corresponding to the page, both state records and extent
3275 * map records are removed
3277 int try_release_extent_mapping(struct extent_map_tree *map,
3278 struct extent_io_tree *tree, struct page *page,
3281 struct extent_map *em;
3282 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
3283 u64 end = start + PAGE_CACHE_SIZE - 1;
3285 if ((mask & __GFP_WAIT) &&
3286 page->mapping->host->i_size > 16 * 1024 * 1024) {
3288 while (start <= end) {
3289 len = end - start + 1;
3290 write_lock(&map->lock);
3291 em = lookup_extent_mapping(map, start, len);
3292 if (IS_ERR_OR_NULL(em)) {
3293 write_unlock(&map->lock);
3296 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
3297 em->start != start) {
3298 write_unlock(&map->lock);
3299 free_extent_map(em);
3302 if (!test_range_bit(tree, em->start,
3303 extent_map_end(em) - 1,
3304 EXTENT_LOCKED | EXTENT_WRITEBACK,
3306 remove_extent_mapping(map, em);
3307 /* once for the rb tree */
3308 free_extent_map(em);
3310 start = extent_map_end(em);
3311 write_unlock(&map->lock);
3314 free_extent_map(em);
3317 return try_release_extent_state(map, tree, page, mask);
3321 * helper function for fiemap, which doesn't want to see any holes.
3322 * This maps until we find something past 'last'
3324 static struct extent_map *get_extent_skip_holes(struct inode *inode,
3327 get_extent_t *get_extent)
3329 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
3330 struct extent_map *em;
3337 len = last - offset;
3340 len = (len + sectorsize - 1) & ~(sectorsize - 1);
3341 em = get_extent(inode, NULL, 0, offset, len, 0);
3342 if (IS_ERR_OR_NULL(em))
3345 /* if this isn't a hole return it */
3346 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
3347 em->block_start != EXTENT_MAP_HOLE) {
3351 /* this is a hole, advance to the next extent */
3352 offset = extent_map_end(em);
3353 free_extent_map(em);
3360 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3361 __u64 start, __u64 len, get_extent_t *get_extent)
3365 u64 max = start + len;
3369 u64 last_for_get_extent = 0;
3371 u64 isize = i_size_read(inode);
3372 struct btrfs_key found_key;
3373 struct extent_map *em = NULL;
3374 struct extent_state *cached_state = NULL;
3375 struct btrfs_path *path;
3376 struct btrfs_file_extent_item *item;
3381 unsigned long emflags;
3386 path = btrfs_alloc_path();
3389 path->leave_spinning = 1;
3391 start = ALIGN(start, BTRFS_I(inode)->root->sectorsize);
3392 len = ALIGN(len, BTRFS_I(inode)->root->sectorsize);
3395 * lookup the last file extent. We're not using i_size here
3396 * because there might be preallocation past i_size
3398 ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
3399 path, btrfs_ino(inode), -1, 0);
3401 btrfs_free_path(path);
3406 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3407 struct btrfs_file_extent_item);
3408 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
3409 found_type = btrfs_key_type(&found_key);
3411 /* No extents, but there might be delalloc bits */
3412 if (found_key.objectid != btrfs_ino(inode) ||
3413 found_type != BTRFS_EXTENT_DATA_KEY) {
3414 /* have to trust i_size as the end */
3416 last_for_get_extent = isize;
3419 * remember the start of the last extent. There are a
3420 * bunch of different factors that go into the length of the
3421 * extent, so its much less complex to remember where it started
3423 last = found_key.offset;
3424 last_for_get_extent = last + 1;
3426 btrfs_free_path(path);
3429 * we might have some extents allocated but more delalloc past those
3430 * extents. so, we trust isize unless the start of the last extent is
3435 last_for_get_extent = isize;
3438 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
3439 &cached_state, GFP_NOFS);
3441 em = get_extent_skip_holes(inode, start, last_for_get_extent,
3451 u64 offset_in_extent;
3453 /* break if the extent we found is outside the range */
3454 if (em->start >= max || extent_map_end(em) < off)
3458 * get_extent may return an extent that starts before our
3459 * requested range. We have to make sure the ranges
3460 * we return to fiemap always move forward and don't
3461 * overlap, so adjust the offsets here
3463 em_start = max(em->start, off);
3466 * record the offset from the start of the extent
3467 * for adjusting the disk offset below
3469 offset_in_extent = em_start - em->start;
3470 em_end = extent_map_end(em);
3471 em_len = em_end - em_start;
3472 emflags = em->flags;
3477 * bump off for our next call to get_extent
3479 off = extent_map_end(em);
3483 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
3485 flags |= FIEMAP_EXTENT_LAST;
3486 } else if (em->block_start == EXTENT_MAP_INLINE) {
3487 flags |= (FIEMAP_EXTENT_DATA_INLINE |
3488 FIEMAP_EXTENT_NOT_ALIGNED);
3489 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
3490 flags |= (FIEMAP_EXTENT_DELALLOC |
3491 FIEMAP_EXTENT_UNKNOWN);
3493 disko = em->block_start + offset_in_extent;
3495 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
3496 flags |= FIEMAP_EXTENT_ENCODED;
3498 free_extent_map(em);
3500 if ((em_start >= last) || em_len == (u64)-1 ||
3501 (last == (u64)-1 && isize <= em_end)) {
3502 flags |= FIEMAP_EXTENT_LAST;
3506 /* now scan forward to see if this is really the last extent. */
3507 em = get_extent_skip_holes(inode, off, last_for_get_extent,
3514 flags |= FIEMAP_EXTENT_LAST;
3517 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
3523 free_extent_map(em);
3525 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len,
3526 &cached_state, GFP_NOFS);
3530 inline struct page *extent_buffer_page(struct extent_buffer *eb,
3534 struct address_space *mapping;
3537 return eb->first_page;
3538 i += eb->start >> PAGE_CACHE_SHIFT;
3539 mapping = eb->first_page->mapping;
3544 * extent_buffer_page is only called after pinning the page
3545 * by increasing the reference count. So we know the page must
3546 * be in the radix tree.
3549 p = radix_tree_lookup(&mapping->page_tree, i);
3555 inline unsigned long num_extent_pages(u64 start, u64 len)
3557 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
3558 (start >> PAGE_CACHE_SHIFT);
3561 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
3566 struct extent_buffer *eb = NULL;
3568 unsigned long flags;
3571 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
3576 rwlock_init(&eb->lock);
3577 atomic_set(&eb->write_locks, 0);
3578 atomic_set(&eb->read_locks, 0);
3579 atomic_set(&eb->blocking_readers, 0);
3580 atomic_set(&eb->blocking_writers, 0);
3581 atomic_set(&eb->spinning_readers, 0);
3582 atomic_set(&eb->spinning_writers, 0);
3583 eb->lock_nested = 0;
3584 init_waitqueue_head(&eb->write_lock_wq);
3585 init_waitqueue_head(&eb->read_lock_wq);
3588 spin_lock_irqsave(&leak_lock, flags);
3589 list_add(&eb->leak_list, &buffers);
3590 spin_unlock_irqrestore(&leak_lock, flags);
3592 atomic_set(&eb->refs, 1);
3597 static void __free_extent_buffer(struct extent_buffer *eb)
3600 unsigned long flags;
3601 spin_lock_irqsave(&leak_lock, flags);
3602 list_del(&eb->leak_list);
3603 spin_unlock_irqrestore(&leak_lock, flags);
3605 kmem_cache_free(extent_buffer_cache, eb);
3609 * Helper for releasing extent buffer page.
3611 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
3612 unsigned long start_idx)
3614 unsigned long index;
3617 if (!eb->first_page)
3620 index = num_extent_pages(eb->start, eb->len);
3621 if (start_idx >= index)
3626 page = extent_buffer_page(eb, index);
3628 page_cache_release(page);
3629 } while (index != start_idx);
3633 * Helper for releasing the extent buffer.
3635 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
3637 btrfs_release_extent_buffer_page(eb, 0);
3638 __free_extent_buffer(eb);
3641 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
3642 u64 start, unsigned long len,
3645 unsigned long num_pages = num_extent_pages(start, len);
3647 unsigned long index = start >> PAGE_CACHE_SHIFT;
3648 struct extent_buffer *eb;
3649 struct extent_buffer *exists = NULL;
3651 struct address_space *mapping = tree->mapping;
3656 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3657 if (eb && atomic_inc_not_zero(&eb->refs)) {
3659 mark_page_accessed(eb->first_page);
3664 eb = __alloc_extent_buffer(tree, start, len, GFP_NOFS);
3669 eb->first_page = page0;
3672 page_cache_get(page0);
3673 mark_page_accessed(page0);
3674 set_page_extent_mapped(page0);
3675 set_page_extent_head(page0, len);
3676 uptodate = PageUptodate(page0);
3680 for (; i < num_pages; i++, index++) {
3681 p = find_or_create_page(mapping, index, GFP_NOFS);
3686 set_page_extent_mapped(p);
3687 mark_page_accessed(p);
3690 set_page_extent_head(p, len);
3692 set_page_private(p, EXTENT_PAGE_PRIVATE);
3694 if (!PageUptodate(p))
3698 * see below about how we avoid a nasty race with release page
3699 * and why we unlock later
3705 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3707 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
3711 spin_lock(&tree->buffer_lock);
3712 ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
3713 if (ret == -EEXIST) {
3714 exists = radix_tree_lookup(&tree->buffer,
3715 start >> PAGE_CACHE_SHIFT);
3716 /* add one reference for the caller */
3717 atomic_inc(&exists->refs);
3718 spin_unlock(&tree->buffer_lock);
3719 radix_tree_preload_end();
3722 /* add one reference for the tree */
3723 atomic_inc(&eb->refs);
3724 spin_unlock(&tree->buffer_lock);
3725 radix_tree_preload_end();
3728 * there is a race where release page may have
3729 * tried to find this extent buffer in the radix
3730 * but failed. It will tell the VM it is safe to
3731 * reclaim the, and it will clear the page private bit.
3732 * We must make sure to set the page private bit properly
3733 * after the extent buffer is in the radix tree so
3734 * it doesn't get lost
3736 set_page_extent_mapped(eb->first_page);
3737 set_page_extent_head(eb->first_page, eb->len);
3739 unlock_page(eb->first_page);
3743 if (eb->first_page && !page0)
3744 unlock_page(eb->first_page);
3746 if (!atomic_dec_and_test(&eb->refs))
3748 btrfs_release_extent_buffer(eb);
3752 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
3753 u64 start, unsigned long len)
3755 struct extent_buffer *eb;
3758 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3759 if (eb && atomic_inc_not_zero(&eb->refs)) {
3761 mark_page_accessed(eb->first_page);
3769 void free_extent_buffer(struct extent_buffer *eb)
3774 if (!atomic_dec_and_test(&eb->refs))
3780 int clear_extent_buffer_dirty(struct extent_io_tree *tree,
3781 struct extent_buffer *eb)
3784 unsigned long num_pages;
3787 num_pages = num_extent_pages(eb->start, eb->len);
3789 for (i = 0; i < num_pages; i++) {
3790 page = extent_buffer_page(eb, i);
3791 if (!PageDirty(page))
3795 WARN_ON(!PagePrivate(page));
3797 set_page_extent_mapped(page);
3799 set_page_extent_head(page, eb->len);
3801 clear_page_dirty_for_io(page);
3802 spin_lock_irq(&page->mapping->tree_lock);
3803 if (!PageDirty(page)) {
3804 radix_tree_tag_clear(&page->mapping->page_tree,
3806 PAGECACHE_TAG_DIRTY);
3808 spin_unlock_irq(&page->mapping->tree_lock);
3809 ClearPageError(page);
3815 int set_extent_buffer_dirty(struct extent_io_tree *tree,
3816 struct extent_buffer *eb)
3819 unsigned long num_pages;
3822 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
3823 num_pages = num_extent_pages(eb->start, eb->len);
3824 for (i = 0; i < num_pages; i++)
3825 __set_page_dirty_nobuffers(extent_buffer_page(eb, i));
3829 static int __eb_straddles_pages(u64 start, u64 len)
3831 if (len < PAGE_CACHE_SIZE)
3833 if (start & (PAGE_CACHE_SIZE - 1))
3835 if ((start + len) & (PAGE_CACHE_SIZE - 1))
3840 static int eb_straddles_pages(struct extent_buffer *eb)
3842 return __eb_straddles_pages(eb->start, eb->len);
3845 int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
3846 struct extent_buffer *eb,
3847 struct extent_state **cached_state)
3851 unsigned long num_pages;
3853 num_pages = num_extent_pages(eb->start, eb->len);
3854 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3856 if (eb_straddles_pages(eb)) {
3857 clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3858 cached_state, GFP_NOFS);
3860 for (i = 0; i < num_pages; i++) {
3861 page = extent_buffer_page(eb, i);
3863 ClearPageUptodate(page);
3868 int set_extent_buffer_uptodate(struct extent_io_tree *tree,
3869 struct extent_buffer *eb)
3873 unsigned long num_pages;
3875 num_pages = num_extent_pages(eb->start, eb->len);
3877 if (eb_straddles_pages(eb)) {
3878 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3881 for (i = 0; i < num_pages; i++) {
3882 page = extent_buffer_page(eb, i);
3883 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
3884 ((i == num_pages - 1) &&
3885 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
3886 check_page_uptodate(tree, page);
3889 SetPageUptodate(page);
3894 int extent_range_uptodate(struct extent_io_tree *tree,
3899 int pg_uptodate = 1;
3901 unsigned long index;
3903 if (__eb_straddles_pages(start, end - start + 1)) {
3904 ret = test_range_bit(tree, start, end,
3905 EXTENT_UPTODATE, 1, NULL);
3909 while (start <= end) {
3910 index = start >> PAGE_CACHE_SHIFT;
3911 page = find_get_page(tree->mapping, index);
3914 uptodate = PageUptodate(page);
3915 page_cache_release(page);
3920 start += PAGE_CACHE_SIZE;
3925 int extent_buffer_uptodate(struct extent_io_tree *tree,
3926 struct extent_buffer *eb,
3927 struct extent_state *cached_state)
3930 unsigned long num_pages;
3933 int pg_uptodate = 1;
3935 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3938 if (eb_straddles_pages(eb)) {
3939 ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3940 EXTENT_UPTODATE, 1, cached_state);
3945 num_pages = num_extent_pages(eb->start, eb->len);
3946 for (i = 0; i < num_pages; i++) {
3947 page = extent_buffer_page(eb, i);
3948 if (!PageUptodate(page)) {
3956 int read_extent_buffer_pages(struct extent_io_tree *tree,
3957 struct extent_buffer *eb, u64 start, int wait,
3958 get_extent_t *get_extent, int mirror_num)
3961 unsigned long start_i;
3965 int locked_pages = 0;
3966 int all_uptodate = 1;
3967 int inc_all_pages = 0;
3968 unsigned long num_pages;
3969 struct bio *bio = NULL;
3970 unsigned long bio_flags = 0;
3972 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3975 if (eb_straddles_pages(eb)) {
3976 if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3977 EXTENT_UPTODATE, 1, NULL)) {
3983 WARN_ON(start < eb->start);
3984 start_i = (start >> PAGE_CACHE_SHIFT) -
3985 (eb->start >> PAGE_CACHE_SHIFT);
3990 num_pages = num_extent_pages(eb->start, eb->len);
3991 for (i = start_i; i < num_pages; i++) {
3992 page = extent_buffer_page(eb, i);
3993 if (wait == WAIT_NONE) {
3994 if (!trylock_page(page))
4000 if (!PageUptodate(page))
4005 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4009 for (i = start_i; i < num_pages; i++) {
4010 page = extent_buffer_page(eb, i);
4012 WARN_ON(!PagePrivate(page));
4014 set_page_extent_mapped(page);
4016 set_page_extent_head(page, eb->len);
4019 page_cache_get(page);
4020 if (!PageUptodate(page)) {
4023 ClearPageError(page);
4024 err = __extent_read_full_page(tree, page,
4026 mirror_num, &bio_flags);
4035 submit_one_bio(READ, bio, mirror_num, bio_flags);
4037 if (ret || wait != WAIT_COMPLETE)
4040 for (i = start_i; i < num_pages; i++) {
4041 page = extent_buffer_page(eb, i);
4042 wait_on_page_locked(page);
4043 if (!PageUptodate(page))
4048 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4053 while (locked_pages > 0) {
4054 page = extent_buffer_page(eb, i);
4062 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
4063 unsigned long start,
4070 char *dst = (char *)dstv;
4071 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4072 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4074 WARN_ON(start > eb->len);
4075 WARN_ON(start + len > eb->start + eb->len);
4077 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4080 page = extent_buffer_page(eb, i);
4082 cur = min(len, (PAGE_CACHE_SIZE - offset));
4083 kaddr = page_address(page);
4084 memcpy(dst, kaddr + offset, cur);
4093 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
4094 unsigned long min_len, char **map,
4095 unsigned long *map_start,
4096 unsigned long *map_len)
4098 size_t offset = start & (PAGE_CACHE_SIZE - 1);
4101 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4102 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4103 unsigned long end_i = (start_offset + start + min_len - 1) >>
4110 offset = start_offset;
4114 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
4117 if (start + min_len > eb->len) {
4118 printk(KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
4119 "wanted %lu %lu\n", (unsigned long long)eb->start,
4120 eb->len, start, min_len);
4125 p = extent_buffer_page(eb, i);
4126 kaddr = page_address(p);
4127 *map = kaddr + offset;
4128 *map_len = PAGE_CACHE_SIZE - offset;
4132 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
4133 unsigned long start,
4140 char *ptr = (char *)ptrv;
4141 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4142 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4145 WARN_ON(start > eb->len);
4146 WARN_ON(start + len > eb->start + eb->len);
4148 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4151 page = extent_buffer_page(eb, i);
4153 cur = min(len, (PAGE_CACHE_SIZE - offset));
4155 kaddr = page_address(page);
4156 ret = memcmp(ptr, kaddr + offset, cur);
4168 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
4169 unsigned long start, unsigned long len)
4175 char *src = (char *)srcv;
4176 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4177 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4179 WARN_ON(start > eb->len);
4180 WARN_ON(start + len > eb->start + eb->len);
4182 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4185 page = extent_buffer_page(eb, i);
4186 WARN_ON(!PageUptodate(page));
4188 cur = min(len, PAGE_CACHE_SIZE - offset);
4189 kaddr = page_address(page);
4190 memcpy(kaddr + offset, src, cur);
4199 void memset_extent_buffer(struct extent_buffer *eb, char c,
4200 unsigned long start, unsigned long len)
4206 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4207 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4209 WARN_ON(start > eb->len);
4210 WARN_ON(start + len > eb->start + eb->len);
4212 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4215 page = extent_buffer_page(eb, i);
4216 WARN_ON(!PageUptodate(page));
4218 cur = min(len, PAGE_CACHE_SIZE - offset);
4219 kaddr = page_address(page);
4220 memset(kaddr + offset, c, cur);
4228 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
4229 unsigned long dst_offset, unsigned long src_offset,
4232 u64 dst_len = dst->len;
4237 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4238 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4240 WARN_ON(src->len != dst_len);
4242 offset = (start_offset + dst_offset) &
4243 ((unsigned long)PAGE_CACHE_SIZE - 1);
4246 page = extent_buffer_page(dst, i);
4247 WARN_ON(!PageUptodate(page));
4249 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
4251 kaddr = page_address(page);
4252 read_extent_buffer(src, kaddr + offset, src_offset, cur);
4261 static void move_pages(struct page *dst_page, struct page *src_page,
4262 unsigned long dst_off, unsigned long src_off,
4265 char *dst_kaddr = page_address(dst_page);
4266 if (dst_page == src_page) {
4267 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
4269 char *src_kaddr = page_address(src_page);
4270 char *p = dst_kaddr + dst_off + len;
4271 char *s = src_kaddr + src_off + len;
4278 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
4280 unsigned long distance = (src > dst) ? src - dst : dst - src;
4281 return distance < len;
4284 static void copy_pages(struct page *dst_page, struct page *src_page,
4285 unsigned long dst_off, unsigned long src_off,
4288 char *dst_kaddr = page_address(dst_page);
4291 if (dst_page != src_page) {
4292 src_kaddr = page_address(src_page);
4294 src_kaddr = dst_kaddr;
4295 BUG_ON(areas_overlap(src_off, dst_off, len));
4298 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
4301 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
4302 unsigned long src_offset, unsigned long len)
4305 size_t dst_off_in_page;
4306 size_t src_off_in_page;
4307 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4308 unsigned long dst_i;
4309 unsigned long src_i;
4311 if (src_offset + len > dst->len) {
4312 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4313 "len %lu dst len %lu\n", src_offset, len, dst->len);
4316 if (dst_offset + len > dst->len) {
4317 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4318 "len %lu dst len %lu\n", dst_offset, len, dst->len);
4323 dst_off_in_page = (start_offset + dst_offset) &
4324 ((unsigned long)PAGE_CACHE_SIZE - 1);
4325 src_off_in_page = (start_offset + src_offset) &
4326 ((unsigned long)PAGE_CACHE_SIZE - 1);
4328 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4329 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
4331 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
4333 cur = min_t(unsigned long, cur,
4334 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
4336 copy_pages(extent_buffer_page(dst, dst_i),
4337 extent_buffer_page(dst, src_i),
4338 dst_off_in_page, src_off_in_page, cur);
4346 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
4347 unsigned long src_offset, unsigned long len)
4350 size_t dst_off_in_page;
4351 size_t src_off_in_page;
4352 unsigned long dst_end = dst_offset + len - 1;
4353 unsigned long src_end = src_offset + len - 1;
4354 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4355 unsigned long dst_i;
4356 unsigned long src_i;
4358 if (src_offset + len > dst->len) {
4359 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4360 "len %lu len %lu\n", src_offset, len, dst->len);
4363 if (dst_offset + len > dst->len) {
4364 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4365 "len %lu len %lu\n", dst_offset, len, dst->len);
4368 if (!areas_overlap(src_offset, dst_offset, len)) {
4369 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
4373 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
4374 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
4376 dst_off_in_page = (start_offset + dst_end) &
4377 ((unsigned long)PAGE_CACHE_SIZE - 1);
4378 src_off_in_page = (start_offset + src_end) &
4379 ((unsigned long)PAGE_CACHE_SIZE - 1);
4381 cur = min_t(unsigned long, len, src_off_in_page + 1);
4382 cur = min(cur, dst_off_in_page + 1);
4383 move_pages(extent_buffer_page(dst, dst_i),
4384 extent_buffer_page(dst, src_i),
4385 dst_off_in_page - cur + 1,
4386 src_off_in_page - cur + 1, cur);
4394 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
4396 struct extent_buffer *eb =
4397 container_of(head, struct extent_buffer, rcu_head);
4399 btrfs_release_extent_buffer(eb);
4402 int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
4404 u64 start = page_offset(page);
4405 struct extent_buffer *eb;
4408 spin_lock(&tree->buffer_lock);
4409 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4411 spin_unlock(&tree->buffer_lock);
4415 if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
4421 * set @eb->refs to 0 if it is already 1, and then release the @eb.
4424 if (atomic_cmpxchg(&eb->refs, 1, 0) != 1) {
4429 radix_tree_delete(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4431 spin_unlock(&tree->buffer_lock);
4433 /* at this point we can safely release the extent buffer */
4434 if (atomic_read(&eb->refs) == 0)
4435 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);