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"
22 static struct kmem_cache *extent_state_cache;
23 static struct kmem_cache *extent_buffer_cache;
25 static LIST_HEAD(buffers);
26 static LIST_HEAD(states);
30 static DEFINE_SPINLOCK(leak_lock);
33 #define BUFFER_LRU_MAX 64
38 struct rb_node rb_node;
41 struct extent_page_data {
43 struct extent_io_tree *tree;
44 get_extent_t *get_extent;
46 /* tells writepage not to lock the state bits for this range
47 * it still does the unlocking
49 unsigned int extent_locked:1;
51 /* tells the submit_bio code to use a WRITE_SYNC */
52 unsigned int sync_io:1;
55 int __init extent_io_init(void)
57 extent_state_cache = kmem_cache_create("extent_state",
58 sizeof(struct extent_state), 0,
59 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
60 if (!extent_state_cache)
63 extent_buffer_cache = kmem_cache_create("extent_buffers",
64 sizeof(struct extent_buffer), 0,
65 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
66 if (!extent_buffer_cache)
67 goto free_state_cache;
71 kmem_cache_destroy(extent_state_cache);
75 void extent_io_exit(void)
77 struct extent_state *state;
78 struct extent_buffer *eb;
80 while (!list_empty(&states)) {
81 state = list_entry(states.next, struct extent_state, leak_list);
82 printk(KERN_ERR "btrfs state leak: start %llu end %llu "
83 "state %lu in tree %p refs %d\n",
84 (unsigned long long)state->start,
85 (unsigned long long)state->end,
86 state->state, state->tree, atomic_read(&state->refs));
87 list_del(&state->leak_list);
88 kmem_cache_free(extent_state_cache, state);
92 while (!list_empty(&buffers)) {
93 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
94 printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
95 "refs %d\n", (unsigned long long)eb->start,
96 eb->len, atomic_read(&eb->refs));
97 list_del(&eb->leak_list);
98 kmem_cache_free(extent_buffer_cache, eb);
100 if (extent_state_cache)
101 kmem_cache_destroy(extent_state_cache);
102 if (extent_buffer_cache)
103 kmem_cache_destroy(extent_buffer_cache);
106 void extent_io_tree_init(struct extent_io_tree *tree,
107 struct address_space *mapping)
109 tree->state = RB_ROOT;
110 INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
112 tree->dirty_bytes = 0;
113 spin_lock_init(&tree->lock);
114 spin_lock_init(&tree->buffer_lock);
115 tree->mapping = mapping;
118 static struct extent_state *alloc_extent_state(gfp_t mask)
120 struct extent_state *state;
125 state = kmem_cache_alloc(extent_state_cache, mask);
132 spin_lock_irqsave(&leak_lock, flags);
133 list_add(&state->leak_list, &states);
134 spin_unlock_irqrestore(&leak_lock, flags);
136 atomic_set(&state->refs, 1);
137 init_waitqueue_head(&state->wq);
141 void free_extent_state(struct extent_state *state)
145 if (atomic_dec_and_test(&state->refs)) {
149 WARN_ON(state->tree);
151 spin_lock_irqsave(&leak_lock, flags);
152 list_del(&state->leak_list);
153 spin_unlock_irqrestore(&leak_lock, flags);
155 kmem_cache_free(extent_state_cache, state);
159 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
160 struct rb_node *node)
162 struct rb_node **p = &root->rb_node;
163 struct rb_node *parent = NULL;
164 struct tree_entry *entry;
168 entry = rb_entry(parent, struct tree_entry, rb_node);
170 if (offset < entry->start)
172 else if (offset > entry->end)
178 entry = rb_entry(node, struct tree_entry, rb_node);
179 rb_link_node(node, parent, p);
180 rb_insert_color(node, root);
184 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
185 struct rb_node **prev_ret,
186 struct rb_node **next_ret)
188 struct rb_root *root = &tree->state;
189 struct rb_node *n = root->rb_node;
190 struct rb_node *prev = NULL;
191 struct rb_node *orig_prev = NULL;
192 struct tree_entry *entry;
193 struct tree_entry *prev_entry = NULL;
196 entry = rb_entry(n, struct tree_entry, rb_node);
200 if (offset < entry->start)
202 else if (offset > entry->end)
210 while (prev && offset > prev_entry->end) {
211 prev = rb_next(prev);
212 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
219 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
220 while (prev && offset < prev_entry->start) {
221 prev = rb_prev(prev);
222 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
229 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
232 struct rb_node *prev = NULL;
235 ret = __etree_search(tree, offset, &prev, NULL);
241 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
242 struct extent_state *other)
244 if (tree->ops && tree->ops->merge_extent_hook)
245 tree->ops->merge_extent_hook(tree->mapping->host, new,
250 * utility function to look for merge candidates inside a given range.
251 * Any extents with matching state are merged together into a single
252 * extent in the tree. Extents with EXTENT_IO in their state field
253 * are not merged because the end_io handlers need to be able to do
254 * operations on them without sleeping (or doing allocations/splits).
256 * This should be called with the tree lock held.
258 static void merge_state(struct extent_io_tree *tree,
259 struct extent_state *state)
261 struct extent_state *other;
262 struct rb_node *other_node;
264 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
267 other_node = rb_prev(&state->rb_node);
269 other = rb_entry(other_node, struct extent_state, rb_node);
270 if (other->end == state->start - 1 &&
271 other->state == state->state) {
272 merge_cb(tree, state, other);
273 state->start = other->start;
275 rb_erase(&other->rb_node, &tree->state);
276 free_extent_state(other);
279 other_node = rb_next(&state->rb_node);
281 other = rb_entry(other_node, struct extent_state, rb_node);
282 if (other->start == state->end + 1 &&
283 other->state == state->state) {
284 merge_cb(tree, state, other);
285 state->end = other->end;
287 rb_erase(&other->rb_node, &tree->state);
288 free_extent_state(other);
293 static void set_state_cb(struct extent_io_tree *tree,
294 struct extent_state *state, int *bits)
296 if (tree->ops && tree->ops->set_bit_hook)
297 tree->ops->set_bit_hook(tree->mapping->host, state, bits);
300 static void clear_state_cb(struct extent_io_tree *tree,
301 struct extent_state *state, int *bits)
303 if (tree->ops && tree->ops->clear_bit_hook)
304 tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
307 static void set_state_bits(struct extent_io_tree *tree,
308 struct extent_state *state, int *bits);
311 * insert an extent_state struct into the tree. 'bits' are set on the
312 * struct before it is inserted.
314 * This may return -EEXIST if the extent is already there, in which case the
315 * state struct is freed.
317 * The tree lock is not taken internally. This is a utility function and
318 * probably isn't what you want to call (see set/clear_extent_bit).
320 static int insert_state(struct extent_io_tree *tree,
321 struct extent_state *state, u64 start, u64 end,
324 struct rb_node *node;
327 printk(KERN_ERR "btrfs end < start %llu %llu\n",
328 (unsigned long long)end,
329 (unsigned long long)start);
332 state->start = start;
335 set_state_bits(tree, state, bits);
337 node = tree_insert(&tree->state, end, &state->rb_node);
339 struct extent_state *found;
340 found = rb_entry(node, struct extent_state, rb_node);
341 printk(KERN_ERR "btrfs found node %llu %llu on insert of "
342 "%llu %llu\n", (unsigned long long)found->start,
343 (unsigned long long)found->end,
344 (unsigned long long)start, (unsigned long long)end);
348 merge_state(tree, state);
352 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
355 if (tree->ops && tree->ops->split_extent_hook)
356 tree->ops->split_extent_hook(tree->mapping->host, orig, split);
360 * split a given extent state struct in two, inserting the preallocated
361 * struct 'prealloc' as the newly created second half. 'split' indicates an
362 * offset inside 'orig' where it should be split.
365 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
366 * are two extent state structs in the tree:
367 * prealloc: [orig->start, split - 1]
368 * orig: [ split, orig->end ]
370 * The tree locks are not taken by this function. They need to be held
373 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
374 struct extent_state *prealloc, u64 split)
376 struct rb_node *node;
378 split_cb(tree, orig, split);
380 prealloc->start = orig->start;
381 prealloc->end = split - 1;
382 prealloc->state = orig->state;
385 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
387 free_extent_state(prealloc);
390 prealloc->tree = tree;
395 * utility function to clear some bits in an extent state struct.
396 * it will optionally wake up any one waiting on this state (wake == 1), or
397 * forcibly remove the state from the tree (delete == 1).
399 * If no bits are set on the state struct after clearing things, the
400 * struct is freed and removed from the tree
402 static int clear_state_bit(struct extent_io_tree *tree,
403 struct extent_state *state,
406 int bits_to_clear = *bits & ~EXTENT_CTLBITS;
407 int ret = state->state & bits_to_clear;
409 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
410 u64 range = state->end - state->start + 1;
411 WARN_ON(range > tree->dirty_bytes);
412 tree->dirty_bytes -= range;
414 clear_state_cb(tree, state, bits);
415 state->state &= ~bits_to_clear;
418 if (state->state == 0) {
420 rb_erase(&state->rb_node, &tree->state);
422 free_extent_state(state);
427 merge_state(tree, state);
432 static struct extent_state *
433 alloc_extent_state_atomic(struct extent_state *prealloc)
436 prealloc = alloc_extent_state(GFP_ATOMIC);
442 * clear some bits on a range in the tree. This may require splitting
443 * or inserting elements in the tree, so the gfp mask is used to
444 * indicate which allocations or sleeping are allowed.
446 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
447 * the given range from the tree regardless of state (ie for truncate).
449 * the range [start, end] is inclusive.
451 * This takes the tree lock, and returns < 0 on error, > 0 if any of the
452 * bits were already set, or zero if none of the bits were already set.
454 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
455 int bits, int wake, int delete,
456 struct extent_state **cached_state,
459 struct extent_state *state;
460 struct extent_state *cached;
461 struct extent_state *prealloc = NULL;
462 struct rb_node *next_node;
463 struct rb_node *node;
470 bits |= ~EXTENT_CTLBITS;
471 bits |= EXTENT_FIRST_DELALLOC;
473 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
476 if (!prealloc && (mask & __GFP_WAIT)) {
477 prealloc = alloc_extent_state(mask);
482 spin_lock(&tree->lock);
484 cached = *cached_state;
487 *cached_state = NULL;
491 if (cached && cached->tree && cached->start <= start &&
492 cached->end > start) {
494 atomic_dec(&cached->refs);
499 free_extent_state(cached);
502 * this search will find the extents that end after
505 node = tree_search(tree, start);
508 state = rb_entry(node, struct extent_state, rb_node);
510 if (state->start > end)
512 WARN_ON(state->end < start);
513 last_end = state->end;
516 * | ---- desired range ---- |
518 * | ------------- state -------------- |
520 * We need to split the extent we found, and may flip
521 * bits on second half.
523 * If the extent we found extends past our range, we
524 * just split and search again. It'll get split again
525 * the next time though.
527 * If the extent we found is inside our range, we clear
528 * the desired bit on it.
531 if (state->start < start) {
532 prealloc = alloc_extent_state_atomic(prealloc);
534 err = split_state(tree, state, prealloc, start);
535 BUG_ON(err == -EEXIST);
539 if (state->end <= end) {
540 set |= clear_state_bit(tree, state, &bits, wake);
541 if (last_end == (u64)-1)
543 start = last_end + 1;
548 * | ---- desired range ---- |
550 * We need to split the extent, and clear the bit
553 if (state->start <= end && state->end > end) {
554 prealloc = alloc_extent_state_atomic(prealloc);
556 err = split_state(tree, state, prealloc, end + 1);
557 BUG_ON(err == -EEXIST);
561 set |= clear_state_bit(tree, prealloc, &bits, wake);
567 if (state->end < end && prealloc && !need_resched())
568 next_node = rb_next(&state->rb_node);
572 set |= clear_state_bit(tree, state, &bits, wake);
573 if (last_end == (u64)-1)
575 start = last_end + 1;
576 if (start <= end && next_node) {
577 state = rb_entry(next_node, struct extent_state,
579 if (state->start == start)
585 spin_unlock(&tree->lock);
587 free_extent_state(prealloc);
594 spin_unlock(&tree->lock);
595 if (mask & __GFP_WAIT)
600 static int wait_on_state(struct extent_io_tree *tree,
601 struct extent_state *state)
602 __releases(tree->lock)
603 __acquires(tree->lock)
606 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
607 spin_unlock(&tree->lock);
609 spin_lock(&tree->lock);
610 finish_wait(&state->wq, &wait);
615 * waits for one or more bits to clear on a range in the state tree.
616 * The range [start, end] is inclusive.
617 * The tree lock is taken by this function
619 int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
621 struct extent_state *state;
622 struct rb_node *node;
624 spin_lock(&tree->lock);
628 * this search will find all the extents that end after
631 node = tree_search(tree, start);
635 state = rb_entry(node, struct extent_state, rb_node);
637 if (state->start > end)
640 if (state->state & bits) {
641 start = state->start;
642 atomic_inc(&state->refs);
643 wait_on_state(tree, state);
644 free_extent_state(state);
647 start = state->end + 1;
652 cond_resched_lock(&tree->lock);
655 spin_unlock(&tree->lock);
659 static void set_state_bits(struct extent_io_tree *tree,
660 struct extent_state *state,
663 int bits_to_set = *bits & ~EXTENT_CTLBITS;
665 set_state_cb(tree, state, bits);
666 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
667 u64 range = state->end - state->start + 1;
668 tree->dirty_bytes += range;
670 state->state |= bits_to_set;
673 static void cache_state(struct extent_state *state,
674 struct extent_state **cached_ptr)
676 if (cached_ptr && !(*cached_ptr)) {
677 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
679 atomic_inc(&state->refs);
684 static void uncache_state(struct extent_state **cached_ptr)
686 if (cached_ptr && (*cached_ptr)) {
687 struct extent_state *state = *cached_ptr;
689 free_extent_state(state);
694 * set some bits on a range in the tree. This may require allocations or
695 * sleeping, so the gfp mask is used to indicate what is allowed.
697 * If any of the exclusive bits are set, this will fail with -EEXIST if some
698 * part of the range already has the desired bits set. The start of the
699 * existing range is returned in failed_start in this case.
701 * [start, end] is inclusive This takes the tree lock.
704 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
705 int bits, int exclusive_bits, u64 *failed_start,
706 struct extent_state **cached_state, gfp_t mask)
708 struct extent_state *state;
709 struct extent_state *prealloc = NULL;
710 struct rb_node *node;
715 bits |= EXTENT_FIRST_DELALLOC;
717 if (!prealloc && (mask & __GFP_WAIT)) {
718 prealloc = alloc_extent_state(mask);
722 spin_lock(&tree->lock);
723 if (cached_state && *cached_state) {
724 state = *cached_state;
725 if (state->start <= start && state->end > start &&
727 node = &state->rb_node;
732 * this search will find all the extents that end after
735 node = tree_search(tree, start);
737 prealloc = alloc_extent_state_atomic(prealloc);
739 err = insert_state(tree, prealloc, start, end, &bits);
741 BUG_ON(err == -EEXIST);
744 state = rb_entry(node, struct extent_state, rb_node);
746 last_start = state->start;
747 last_end = state->end;
750 * | ---- desired range ---- |
753 * Just lock what we found and keep going
755 if (state->start == start && state->end <= end) {
756 struct rb_node *next_node;
757 if (state->state & exclusive_bits) {
758 *failed_start = state->start;
763 set_state_bits(tree, state, &bits);
765 cache_state(state, cached_state);
766 merge_state(tree, state);
767 if (last_end == (u64)-1)
770 start = last_end + 1;
771 next_node = rb_next(&state->rb_node);
772 if (next_node && start < end && prealloc && !need_resched()) {
773 state = rb_entry(next_node, struct extent_state,
775 if (state->start == start)
782 * | ---- desired range ---- |
785 * | ------------- state -------------- |
787 * We need to split the extent we found, and may flip bits on
790 * If the extent we found extends past our
791 * range, we just split and search again. It'll get split
792 * again the next time though.
794 * If the extent we found is inside our range, we set the
797 if (state->start < start) {
798 if (state->state & exclusive_bits) {
799 *failed_start = start;
804 prealloc = alloc_extent_state_atomic(prealloc);
806 err = split_state(tree, state, prealloc, start);
807 BUG_ON(err == -EEXIST);
811 if (state->end <= end) {
812 set_state_bits(tree, state, &bits);
813 cache_state(state, cached_state);
814 merge_state(tree, state);
815 if (last_end == (u64)-1)
817 start = last_end + 1;
822 * | ---- desired range ---- |
823 * | state | or | state |
825 * There's a hole, we need to insert something in it and
826 * ignore the extent we found.
828 if (state->start > start) {
830 if (end < last_start)
833 this_end = last_start - 1;
835 prealloc = alloc_extent_state_atomic(prealloc);
839 * Avoid to free 'prealloc' if it can be merged with
842 err = insert_state(tree, prealloc, start, this_end,
844 BUG_ON(err == -EEXIST);
846 free_extent_state(prealloc);
850 cache_state(prealloc, cached_state);
852 start = this_end + 1;
856 * | ---- desired range ---- |
858 * We need to split the extent, and set the bit
861 if (state->start <= end && state->end > end) {
862 if (state->state & exclusive_bits) {
863 *failed_start = start;
868 prealloc = alloc_extent_state_atomic(prealloc);
870 err = split_state(tree, state, prealloc, end + 1);
871 BUG_ON(err == -EEXIST);
873 set_state_bits(tree, prealloc, &bits);
874 cache_state(prealloc, cached_state);
875 merge_state(tree, prealloc);
883 spin_unlock(&tree->lock);
885 free_extent_state(prealloc);
892 spin_unlock(&tree->lock);
893 if (mask & __GFP_WAIT)
899 * convert_extent - convert all bits in a given range from one bit to another
900 * @tree: the io tree to search
901 * @start: the start offset in bytes
902 * @end: the end offset in bytes (inclusive)
903 * @bits: the bits to set in this range
904 * @clear_bits: the bits to clear in this range
905 * @mask: the allocation mask
907 * This will go through and set bits for the given range. If any states exist
908 * already in this range they are set with the given bit and cleared of the
909 * clear_bits. This is only meant to be used by things that are mergeable, ie
910 * converting from say DELALLOC to DIRTY. This is not meant to be used with
911 * boundary bits like LOCK.
913 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
914 int bits, int clear_bits, gfp_t mask)
916 struct extent_state *state;
917 struct extent_state *prealloc = NULL;
918 struct rb_node *node;
924 if (!prealloc && (mask & __GFP_WAIT)) {
925 prealloc = alloc_extent_state(mask);
930 spin_lock(&tree->lock);
932 * this search will find all the extents that end after
935 node = tree_search(tree, start);
937 prealloc = alloc_extent_state_atomic(prealloc);
942 err = insert_state(tree, prealloc, start, end, &bits);
944 BUG_ON(err == -EEXIST);
947 state = rb_entry(node, struct extent_state, rb_node);
949 last_start = state->start;
950 last_end = state->end;
953 * | ---- desired range ---- |
956 * Just lock what we found and keep going
958 if (state->start == start && state->end <= end) {
959 struct rb_node *next_node;
961 set_state_bits(tree, state, &bits);
962 clear_state_bit(tree, state, &clear_bits, 0);
964 merge_state(tree, state);
965 if (last_end == (u64)-1)
968 start = last_end + 1;
969 next_node = rb_next(&state->rb_node);
970 if (next_node && start < end && prealloc && !need_resched()) {
971 state = rb_entry(next_node, struct extent_state,
973 if (state->start == start)
980 * | ---- desired range ---- |
983 * | ------------- state -------------- |
985 * We need to split the extent we found, and may flip bits on
988 * If the extent we found extends past our
989 * range, we just split and search again. It'll get split
990 * again the next time though.
992 * If the extent we found is inside our range, we set the
995 if (state->start < start) {
996 prealloc = alloc_extent_state_atomic(prealloc);
1001 err = split_state(tree, state, prealloc, start);
1002 BUG_ON(err == -EEXIST);
1006 if (state->end <= end) {
1007 set_state_bits(tree, state, &bits);
1008 clear_state_bit(tree, state, &clear_bits, 0);
1009 merge_state(tree, state);
1010 if (last_end == (u64)-1)
1012 start = last_end + 1;
1017 * | ---- desired range ---- |
1018 * | state | or | state |
1020 * There's a hole, we need to insert something in it and
1021 * ignore the extent we found.
1023 if (state->start > start) {
1025 if (end < last_start)
1028 this_end = last_start - 1;
1030 prealloc = alloc_extent_state_atomic(prealloc);
1037 * Avoid to free 'prealloc' if it can be merged with
1040 err = insert_state(tree, prealloc, start, this_end,
1042 BUG_ON(err == -EEXIST);
1044 free_extent_state(prealloc);
1049 start = this_end + 1;
1053 * | ---- desired range ---- |
1055 * We need to split the extent, and set the bit
1058 if (state->start <= end && state->end > end) {
1059 prealloc = alloc_extent_state_atomic(prealloc);
1065 err = split_state(tree, state, prealloc, end + 1);
1066 BUG_ON(err == -EEXIST);
1068 set_state_bits(tree, prealloc, &bits);
1069 clear_state_bit(tree, prealloc, &clear_bits, 0);
1071 merge_state(tree, prealloc);
1079 spin_unlock(&tree->lock);
1081 free_extent_state(prealloc);
1088 spin_unlock(&tree->lock);
1089 if (mask & __GFP_WAIT)
1094 /* wrappers around set/clear extent bit */
1095 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1098 return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
1102 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1103 int bits, gfp_t mask)
1105 return set_extent_bit(tree, start, end, bits, 0, NULL,
1109 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1110 int bits, gfp_t mask)
1112 return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
1115 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
1116 struct extent_state **cached_state, gfp_t mask)
1118 return set_extent_bit(tree, start, end,
1119 EXTENT_DELALLOC | EXTENT_UPTODATE,
1120 0, NULL, cached_state, mask);
1123 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1126 return clear_extent_bit(tree, start, end,
1127 EXTENT_DIRTY | EXTENT_DELALLOC |
1128 EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
1131 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
1134 return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
1138 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
1139 struct extent_state **cached_state, gfp_t mask)
1141 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0,
1142 NULL, cached_state, mask);
1145 static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
1146 u64 end, struct extent_state **cached_state,
1149 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
1150 cached_state, mask);
1154 * either insert or lock state struct between start and end use mask to tell
1155 * us if waiting is desired.
1157 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1158 int bits, struct extent_state **cached_state, gfp_t mask)
1163 err = set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
1164 EXTENT_LOCKED, &failed_start,
1165 cached_state, mask);
1166 if (err == -EEXIST && (mask & __GFP_WAIT)) {
1167 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1168 start = failed_start;
1172 WARN_ON(start > end);
1177 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
1179 return lock_extent_bits(tree, start, end, 0, NULL, mask);
1182 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
1188 err = set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1189 &failed_start, NULL, mask);
1190 if (err == -EEXIST) {
1191 if (failed_start > start)
1192 clear_extent_bit(tree, start, failed_start - 1,
1193 EXTENT_LOCKED, 1, 0, NULL, mask);
1199 int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
1200 struct extent_state **cached, gfp_t mask)
1202 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
1206 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
1208 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
1213 * helper function to set both pages and extents in the tree writeback
1215 static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1217 unsigned long index = start >> PAGE_CACHE_SHIFT;
1218 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1221 while (index <= end_index) {
1222 page = find_get_page(tree->mapping, index);
1224 set_page_writeback(page);
1225 page_cache_release(page);
1231 /* find the first state struct with 'bits' set after 'start', and
1232 * return it. tree->lock must be held. NULL will returned if
1233 * nothing was found after 'start'
1235 struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
1236 u64 start, int bits)
1238 struct rb_node *node;
1239 struct extent_state *state;
1242 * this search will find all the extents that end after
1245 node = tree_search(tree, start);
1250 state = rb_entry(node, struct extent_state, rb_node);
1251 if (state->end >= start && (state->state & bits))
1254 node = rb_next(node);
1263 * find the first offset in the io tree with 'bits' set. zero is
1264 * returned if we find something, and *start_ret and *end_ret are
1265 * set to reflect the state struct that was found.
1267 * If nothing was found, 1 is returned, < 0 on error
1269 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1270 u64 *start_ret, u64 *end_ret, int bits)
1272 struct extent_state *state;
1275 spin_lock(&tree->lock);
1276 state = find_first_extent_bit_state(tree, start, bits);
1278 *start_ret = state->start;
1279 *end_ret = state->end;
1282 spin_unlock(&tree->lock);
1287 * find a contiguous range of bytes in the file marked as delalloc, not
1288 * more than 'max_bytes'. start and end are used to return the range,
1290 * 1 is returned if we find something, 0 if nothing was in the tree
1292 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1293 u64 *start, u64 *end, u64 max_bytes,
1294 struct extent_state **cached_state)
1296 struct rb_node *node;
1297 struct extent_state *state;
1298 u64 cur_start = *start;
1300 u64 total_bytes = 0;
1302 spin_lock(&tree->lock);
1305 * this search will find all the extents that end after
1308 node = tree_search(tree, cur_start);
1316 state = rb_entry(node, struct extent_state, rb_node);
1317 if (found && (state->start != cur_start ||
1318 (state->state & EXTENT_BOUNDARY))) {
1321 if (!(state->state & EXTENT_DELALLOC)) {
1327 *start = state->start;
1328 *cached_state = state;
1329 atomic_inc(&state->refs);
1333 cur_start = state->end + 1;
1334 node = rb_next(node);
1337 total_bytes += state->end - state->start + 1;
1338 if (total_bytes >= max_bytes)
1342 spin_unlock(&tree->lock);
1346 static noinline int __unlock_for_delalloc(struct inode *inode,
1347 struct page *locked_page,
1351 struct page *pages[16];
1352 unsigned long index = start >> PAGE_CACHE_SHIFT;
1353 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1354 unsigned long nr_pages = end_index - index + 1;
1357 if (index == locked_page->index && end_index == index)
1360 while (nr_pages > 0) {
1361 ret = find_get_pages_contig(inode->i_mapping, index,
1362 min_t(unsigned long, nr_pages,
1363 ARRAY_SIZE(pages)), pages);
1364 for (i = 0; i < ret; i++) {
1365 if (pages[i] != locked_page)
1366 unlock_page(pages[i]);
1367 page_cache_release(pages[i]);
1376 static noinline int lock_delalloc_pages(struct inode *inode,
1377 struct page *locked_page,
1381 unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
1382 unsigned long start_index = index;
1383 unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
1384 unsigned long pages_locked = 0;
1385 struct page *pages[16];
1386 unsigned long nrpages;
1390 /* the caller is responsible for locking the start index */
1391 if (index == locked_page->index && index == end_index)
1394 /* skip the page at the start index */
1395 nrpages = end_index - index + 1;
1396 while (nrpages > 0) {
1397 ret = find_get_pages_contig(inode->i_mapping, index,
1398 min_t(unsigned long,
1399 nrpages, ARRAY_SIZE(pages)), pages);
1404 /* now we have an array of pages, lock them all */
1405 for (i = 0; i < ret; i++) {
1407 * the caller is taking responsibility for
1410 if (pages[i] != locked_page) {
1411 lock_page(pages[i]);
1412 if (!PageDirty(pages[i]) ||
1413 pages[i]->mapping != inode->i_mapping) {
1415 unlock_page(pages[i]);
1416 page_cache_release(pages[i]);
1420 page_cache_release(pages[i]);
1429 if (ret && pages_locked) {
1430 __unlock_for_delalloc(inode, locked_page,
1432 ((u64)(start_index + pages_locked - 1)) <<
1439 * find a contiguous range of bytes in the file marked as delalloc, not
1440 * more than 'max_bytes'. start and end are used to return the range,
1442 * 1 is returned if we find something, 0 if nothing was in the tree
1444 static noinline u64 find_lock_delalloc_range(struct inode *inode,
1445 struct extent_io_tree *tree,
1446 struct page *locked_page,
1447 u64 *start, u64 *end,
1453 struct extent_state *cached_state = NULL;
1458 /* step one, find a bunch of delalloc bytes starting at start */
1459 delalloc_start = *start;
1461 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1462 max_bytes, &cached_state);
1463 if (!found || delalloc_end <= *start) {
1464 *start = delalloc_start;
1465 *end = delalloc_end;
1466 free_extent_state(cached_state);
1471 * start comes from the offset of locked_page. We have to lock
1472 * pages in order, so we can't process delalloc bytes before
1475 if (delalloc_start < *start)
1476 delalloc_start = *start;
1479 * make sure to limit the number of pages we try to lock down
1482 if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1483 delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
1485 /* step two, lock all the pages after the page that has start */
1486 ret = lock_delalloc_pages(inode, locked_page,
1487 delalloc_start, delalloc_end);
1488 if (ret == -EAGAIN) {
1489 /* some of the pages are gone, lets avoid looping by
1490 * shortening the size of the delalloc range we're searching
1492 free_extent_state(cached_state);
1494 unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
1495 max_bytes = PAGE_CACHE_SIZE - offset;
1505 /* step three, lock the state bits for the whole range */
1506 lock_extent_bits(tree, delalloc_start, delalloc_end,
1507 0, &cached_state, GFP_NOFS);
1509 /* then test to make sure it is all still delalloc */
1510 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1511 EXTENT_DELALLOC, 1, cached_state);
1513 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1514 &cached_state, GFP_NOFS);
1515 __unlock_for_delalloc(inode, locked_page,
1516 delalloc_start, delalloc_end);
1520 free_extent_state(cached_state);
1521 *start = delalloc_start;
1522 *end = delalloc_end;
1527 int extent_clear_unlock_delalloc(struct inode *inode,
1528 struct extent_io_tree *tree,
1529 u64 start, u64 end, struct page *locked_page,
1533 struct page *pages[16];
1534 unsigned long index = start >> PAGE_CACHE_SHIFT;
1535 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1536 unsigned long nr_pages = end_index - index + 1;
1540 if (op & EXTENT_CLEAR_UNLOCK)
1541 clear_bits |= EXTENT_LOCKED;
1542 if (op & EXTENT_CLEAR_DIRTY)
1543 clear_bits |= EXTENT_DIRTY;
1545 if (op & EXTENT_CLEAR_DELALLOC)
1546 clear_bits |= EXTENT_DELALLOC;
1548 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1549 if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
1550 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
1551 EXTENT_SET_PRIVATE2)))
1554 while (nr_pages > 0) {
1555 ret = find_get_pages_contig(inode->i_mapping, index,
1556 min_t(unsigned long,
1557 nr_pages, ARRAY_SIZE(pages)), pages);
1558 for (i = 0; i < ret; i++) {
1560 if (op & EXTENT_SET_PRIVATE2)
1561 SetPagePrivate2(pages[i]);
1563 if (pages[i] == locked_page) {
1564 page_cache_release(pages[i]);
1567 if (op & EXTENT_CLEAR_DIRTY)
1568 clear_page_dirty_for_io(pages[i]);
1569 if (op & EXTENT_SET_WRITEBACK)
1570 set_page_writeback(pages[i]);
1571 if (op & EXTENT_END_WRITEBACK)
1572 end_page_writeback(pages[i]);
1573 if (op & EXTENT_CLEAR_UNLOCK_PAGE)
1574 unlock_page(pages[i]);
1575 page_cache_release(pages[i]);
1585 * count the number of bytes in the tree that have a given bit(s)
1586 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1587 * cached. The total number found is returned.
1589 u64 count_range_bits(struct extent_io_tree *tree,
1590 u64 *start, u64 search_end, u64 max_bytes,
1591 unsigned long bits, int contig)
1593 struct rb_node *node;
1594 struct extent_state *state;
1595 u64 cur_start = *start;
1596 u64 total_bytes = 0;
1600 if (search_end <= cur_start) {
1605 spin_lock(&tree->lock);
1606 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1607 total_bytes = tree->dirty_bytes;
1611 * this search will find all the extents that end after
1614 node = tree_search(tree, cur_start);
1619 state = rb_entry(node, struct extent_state, rb_node);
1620 if (state->start > search_end)
1622 if (contig && found && state->start > last + 1)
1624 if (state->end >= cur_start && (state->state & bits) == bits) {
1625 total_bytes += min(search_end, state->end) + 1 -
1626 max(cur_start, state->start);
1627 if (total_bytes >= max_bytes)
1630 *start = max(cur_start, state->start);
1634 } else if (contig && found) {
1637 node = rb_next(node);
1642 spin_unlock(&tree->lock);
1647 * set the private field for a given byte offset in the tree. If there isn't
1648 * an extent_state there already, this does nothing.
1650 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1652 struct rb_node *node;
1653 struct extent_state *state;
1656 spin_lock(&tree->lock);
1658 * this search will find all the extents that end after
1661 node = tree_search(tree, start);
1666 state = rb_entry(node, struct extent_state, rb_node);
1667 if (state->start != start) {
1671 state->private = private;
1673 spin_unlock(&tree->lock);
1677 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1679 struct rb_node *node;
1680 struct extent_state *state;
1683 spin_lock(&tree->lock);
1685 * this search will find all the extents that end after
1688 node = tree_search(tree, start);
1693 state = rb_entry(node, struct extent_state, rb_node);
1694 if (state->start != start) {
1698 *private = state->private;
1700 spin_unlock(&tree->lock);
1705 * searches a range in the state tree for a given mask.
1706 * If 'filled' == 1, this returns 1 only if every extent in the tree
1707 * has the bits set. Otherwise, 1 is returned if any bit in the
1708 * range is found set.
1710 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1711 int bits, int filled, struct extent_state *cached)
1713 struct extent_state *state = NULL;
1714 struct rb_node *node;
1717 spin_lock(&tree->lock);
1718 if (cached && cached->tree && cached->start <= start &&
1719 cached->end > start)
1720 node = &cached->rb_node;
1722 node = tree_search(tree, start);
1723 while (node && start <= end) {
1724 state = rb_entry(node, struct extent_state, rb_node);
1726 if (filled && state->start > start) {
1731 if (state->start > end)
1734 if (state->state & bits) {
1738 } else if (filled) {
1743 if (state->end == (u64)-1)
1746 start = state->end + 1;
1749 node = rb_next(node);
1756 spin_unlock(&tree->lock);
1761 * helper function to set a given page up to date if all the
1762 * extents in the tree for that page are up to date
1764 static int check_page_uptodate(struct extent_io_tree *tree,
1767 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1768 u64 end = start + PAGE_CACHE_SIZE - 1;
1769 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1770 SetPageUptodate(page);
1775 * helper function to unlock a page if all the extents in the tree
1776 * for that page are unlocked
1778 static int check_page_locked(struct extent_io_tree *tree,
1781 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
1782 u64 end = start + PAGE_CACHE_SIZE - 1;
1783 if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
1789 * helper function to end page writeback if all the extents
1790 * in the tree for that page are done with writeback
1792 static int check_page_writeback(struct extent_io_tree *tree,
1795 end_page_writeback(page);
1800 * When IO fails, either with EIO or csum verification fails, we
1801 * try other mirrors that might have a good copy of the data. This
1802 * io_failure_record is used to record state as we go through all the
1803 * mirrors. If another mirror has good data, the page is set up to date
1804 * and things continue. If a good mirror can't be found, the original
1805 * bio end_io callback is called to indicate things have failed.
1807 struct io_failure_record {
1812 unsigned long bio_flags;
1818 static int free_io_failure(struct inode *inode, struct io_failure_record *rec,
1823 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1825 set_state_private(failure_tree, rec->start, 0);
1826 ret = clear_extent_bits(failure_tree, rec->start,
1827 rec->start + rec->len - 1,
1828 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
1833 ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
1834 rec->start + rec->len - 1,
1835 EXTENT_DAMAGED, GFP_NOFS);
1844 static void repair_io_failure_callback(struct bio *bio, int err)
1846 complete(bio->bi_private);
1850 * this bypasses the standard btrfs submit functions deliberately, as
1851 * the standard behavior is to write all copies in a raid setup. here we only
1852 * want to write the one bad copy. so we do the mapping for ourselves and issue
1853 * submit_bio directly.
1854 * to avoid any synchonization issues, wait for the data after writing, which
1855 * actually prevents the read that triggered the error from finishing.
1856 * currently, there can be no more than two copies of every data bit. thus,
1857 * exactly one rewrite is required.
1859 int repair_io_failure(struct btrfs_mapping_tree *map_tree, u64 start,
1860 u64 length, u64 logical, struct page *page,
1864 struct btrfs_device *dev;
1865 DECLARE_COMPLETION_ONSTACK(compl);
1868 struct btrfs_bio *bbio = NULL;
1871 BUG_ON(!mirror_num);
1873 bio = bio_alloc(GFP_NOFS, 1);
1876 bio->bi_private = &compl;
1877 bio->bi_end_io = repair_io_failure_callback;
1879 map_length = length;
1881 ret = btrfs_map_block(map_tree, WRITE, logical,
1882 &map_length, &bbio, mirror_num);
1887 BUG_ON(mirror_num != bbio->mirror_num);
1888 sector = bbio->stripes[mirror_num-1].physical >> 9;
1889 bio->bi_sector = sector;
1890 dev = bbio->stripes[mirror_num-1].dev;
1892 if (!dev || !dev->bdev || !dev->writeable) {
1896 bio->bi_bdev = dev->bdev;
1897 bio_add_page(bio, page, length, start-page_offset(page));
1898 submit_bio(WRITE_SYNC, bio);
1899 wait_for_completion(&compl);
1901 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
1902 /* try to remap that extent elsewhere? */
1907 printk(KERN_INFO "btrfs read error corrected: ino %lu off %llu (dev %s "
1908 "sector %llu)\n", page->mapping->host->i_ino, start,
1916 * each time an IO finishes, we do a fast check in the IO failure tree
1917 * to see if we need to process or clean up an io_failure_record
1919 static int clean_io_failure(u64 start, struct page *page)
1922 u64 private_failure;
1923 struct io_failure_record *failrec;
1924 struct btrfs_mapping_tree *map_tree;
1925 struct extent_state *state;
1929 struct inode *inode = page->mapping->host;
1932 ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
1933 (u64)-1, 1, EXTENT_DIRTY, 0);
1937 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree, start,
1942 failrec = (struct io_failure_record *)(unsigned long) private_failure;
1943 BUG_ON(!failrec->this_mirror);
1945 if (failrec->in_validation) {
1946 /* there was no real error, just free the record */
1947 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
1953 spin_lock(&BTRFS_I(inode)->io_tree.lock);
1954 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
1957 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
1959 if (state && state->start == failrec->start) {
1960 map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree;
1961 num_copies = btrfs_num_copies(map_tree, failrec->logical,
1963 if (num_copies > 1) {
1964 ret = repair_io_failure(map_tree, start, failrec->len,
1965 failrec->logical, page,
1966 failrec->failed_mirror);
1973 ret = free_io_failure(inode, failrec, did_repair);
1979 * this is a generic handler for readpage errors (default
1980 * readpage_io_failed_hook). if other copies exist, read those and write back
1981 * good data to the failed position. does not investigate in remapping the
1982 * failed extent elsewhere, hoping the device will be smart enough to do this as
1986 static int bio_readpage_error(struct bio *failed_bio, struct page *page,
1987 u64 start, u64 end, int failed_mirror,
1988 struct extent_state *state)
1990 struct io_failure_record *failrec = NULL;
1992 struct extent_map *em;
1993 struct inode *inode = page->mapping->host;
1994 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1995 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
1996 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2003 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
2005 ret = get_state_private(failure_tree, start, &private);
2007 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2010 failrec->start = start;
2011 failrec->len = end - start + 1;
2012 failrec->this_mirror = 0;
2013 failrec->bio_flags = 0;
2014 failrec->in_validation = 0;
2016 read_lock(&em_tree->lock);
2017 em = lookup_extent_mapping(em_tree, start, failrec->len);
2019 read_unlock(&em_tree->lock);
2024 if (em->start > start || em->start + em->len < start) {
2025 free_extent_map(em);
2028 read_unlock(&em_tree->lock);
2030 if (!em || IS_ERR(em)) {
2034 logical = start - em->start;
2035 logical = em->block_start + logical;
2036 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2037 logical = em->block_start;
2038 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2039 extent_set_compress_type(&failrec->bio_flags,
2042 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2043 "len=%llu\n", logical, start, failrec->len);
2044 failrec->logical = logical;
2045 free_extent_map(em);
2047 /* set the bits in the private failure tree */
2048 ret = set_extent_bits(failure_tree, start, end,
2049 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
2051 ret = set_state_private(failure_tree, start,
2052 (u64)(unsigned long)failrec);
2053 /* set the bits in the inode's tree */
2055 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED,
2062 failrec = (struct io_failure_record *)(unsigned long)private;
2063 pr_debug("bio_readpage_error: (found) logical=%llu, "
2064 "start=%llu, len=%llu, validation=%d\n",
2065 failrec->logical, failrec->start, failrec->len,
2066 failrec->in_validation);
2068 * when data can be on disk more than twice, add to failrec here
2069 * (e.g. with a list for failed_mirror) to make
2070 * clean_io_failure() clean all those errors at once.
2073 num_copies = btrfs_num_copies(
2074 &BTRFS_I(inode)->root->fs_info->mapping_tree,
2075 failrec->logical, failrec->len);
2076 if (num_copies == 1) {
2078 * we only have a single copy of the data, so don't bother with
2079 * all the retry and error correction code that follows. no
2080 * matter what the error is, it is very likely to persist.
2082 pr_debug("bio_readpage_error: cannot repair, num_copies == 1. "
2083 "state=%p, num_copies=%d, next_mirror %d, "
2084 "failed_mirror %d\n", state, num_copies,
2085 failrec->this_mirror, failed_mirror);
2086 free_io_failure(inode, failrec, 0);
2091 spin_lock(&tree->lock);
2092 state = find_first_extent_bit_state(tree, failrec->start,
2094 if (state && state->start != failrec->start)
2096 spin_unlock(&tree->lock);
2100 * there are two premises:
2101 * a) deliver good data to the caller
2102 * b) correct the bad sectors on disk
2104 if (failed_bio->bi_vcnt > 1) {
2106 * to fulfill b), we need to know the exact failing sectors, as
2107 * we don't want to rewrite any more than the failed ones. thus,
2108 * we need separate read requests for the failed bio
2110 * if the following BUG_ON triggers, our validation request got
2111 * merged. we need separate requests for our algorithm to work.
2113 BUG_ON(failrec->in_validation);
2114 failrec->in_validation = 1;
2115 failrec->this_mirror = failed_mirror;
2116 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
2119 * we're ready to fulfill a) and b) alongside. get a good copy
2120 * of the failed sector and if we succeed, we have setup
2121 * everything for repair_io_failure to do the rest for us.
2123 if (failrec->in_validation) {
2124 BUG_ON(failrec->this_mirror != failed_mirror);
2125 failrec->in_validation = 0;
2126 failrec->this_mirror = 0;
2128 failrec->failed_mirror = failed_mirror;
2129 failrec->this_mirror++;
2130 if (failrec->this_mirror == failed_mirror)
2131 failrec->this_mirror++;
2132 read_mode = READ_SYNC;
2135 if (!state || failrec->this_mirror > num_copies) {
2136 pr_debug("bio_readpage_error: (fail) state=%p, num_copies=%d, "
2137 "next_mirror %d, failed_mirror %d\n", state,
2138 num_copies, failrec->this_mirror, failed_mirror);
2139 free_io_failure(inode, failrec, 0);
2143 bio = bio_alloc(GFP_NOFS, 1);
2144 bio->bi_private = state;
2145 bio->bi_end_io = failed_bio->bi_end_io;
2146 bio->bi_sector = failrec->logical >> 9;
2147 bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
2150 bio_add_page(bio, page, failrec->len, start - page_offset(page));
2152 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2153 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode,
2154 failrec->this_mirror, num_copies, failrec->in_validation);
2156 tree->ops->submit_bio_hook(inode, read_mode, bio, failrec->this_mirror,
2157 failrec->bio_flags, 0);
2161 /* lots and lots of room for performance fixes in the end_bio funcs */
2164 * after a writepage IO is done, we need to:
2165 * clear the uptodate bits on error
2166 * clear the writeback bits in the extent tree for this IO
2167 * end_page_writeback if the page has no more pending IO
2169 * Scheduling is not allowed, so the extent state tree is expected
2170 * to have one and only one object corresponding to this IO.
2172 static void end_bio_extent_writepage(struct bio *bio, int err)
2174 int uptodate = err == 0;
2175 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2176 struct extent_io_tree *tree;
2183 struct page *page = bvec->bv_page;
2184 tree = &BTRFS_I(page->mapping->host)->io_tree;
2186 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
2188 end = start + bvec->bv_len - 1;
2190 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
2195 if (--bvec >= bio->bi_io_vec)
2196 prefetchw(&bvec->bv_page->flags);
2197 if (tree->ops && tree->ops->writepage_end_io_hook) {
2198 ret = tree->ops->writepage_end_io_hook(page, start,
2199 end, NULL, uptodate);
2204 if (!uptodate && tree->ops &&
2205 tree->ops->writepage_io_failed_hook) {
2206 ret = tree->ops->writepage_io_failed_hook(bio, page,
2209 uptodate = (err == 0);
2215 clear_extent_uptodate(tree, start, end, NULL, GFP_NOFS);
2216 ClearPageUptodate(page);
2221 end_page_writeback(page);
2223 check_page_writeback(tree, page);
2224 } while (bvec >= bio->bi_io_vec);
2230 * after a readpage IO is done, we need to:
2231 * clear the uptodate bits on error
2232 * set the uptodate bits if things worked
2233 * set the page up to date if all extents in the tree are uptodate
2234 * clear the lock bit in the extent tree
2235 * unlock the page if there are no other extents locked for it
2237 * Scheduling is not allowed, so the extent state tree is expected
2238 * to have one and only one object corresponding to this IO.
2240 static void end_bio_extent_readpage(struct bio *bio, int err)
2242 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
2243 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
2244 struct bio_vec *bvec = bio->bi_io_vec;
2245 struct extent_io_tree *tree;
2255 struct page *page = bvec->bv_page;
2256 struct extent_state *cached = NULL;
2257 struct extent_state *state;
2259 pr_debug("end_bio_extent_readpage: bi_vcnt=%d, idx=%d, err=%d, "
2260 "mirror=%ld\n", bio->bi_vcnt, bio->bi_idx, err,
2261 (long int)bio->bi_bdev);
2262 tree = &BTRFS_I(page->mapping->host)->io_tree;
2264 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
2266 end = start + bvec->bv_len - 1;
2268 if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
2273 if (++bvec <= bvec_end)
2274 prefetchw(&bvec->bv_page->flags);
2276 spin_lock(&tree->lock);
2277 state = find_first_extent_bit_state(tree, start, EXTENT_LOCKED);
2278 if (state && state->start == start) {
2280 * take a reference on the state, unlock will drop
2283 cache_state(state, &cached);
2285 spin_unlock(&tree->lock);
2287 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
2288 ret = tree->ops->readpage_end_io_hook(page, start, end,
2293 clean_io_failure(start, page);
2297 failed_mirror = (int)(unsigned long)bio->bi_bdev;
2299 * The generic bio_readpage_error handles errors the
2300 * following way: If possible, new read requests are
2301 * created and submitted and will end up in
2302 * end_bio_extent_readpage as well (if we're lucky, not
2303 * in the !uptodate case). In that case it returns 0 and
2304 * we just go on with the next page in our bio. If it
2305 * can't handle the error it will return -EIO and we
2306 * remain responsible for that page.
2308 ret = bio_readpage_error(bio, page, start, end,
2309 failed_mirror, NULL);
2313 test_bit(BIO_UPTODATE, &bio->bi_flags);
2316 uncache_state(&cached);
2319 if (tree->ops && tree->ops->readpage_io_failed_hook) {
2320 ret = tree->ops->readpage_io_failed_hook(
2321 bio, page, start, end,
2322 failed_mirror, state);
2329 set_extent_uptodate(tree, start, end, &cached,
2332 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2336 SetPageUptodate(page);
2338 ClearPageUptodate(page);
2344 check_page_uptodate(tree, page);
2346 ClearPageUptodate(page);
2349 check_page_locked(tree, page);
2351 } while (bvec <= bvec_end);
2357 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2362 bio = bio_alloc(gfp_flags, nr_vecs);
2364 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2365 while (!bio && (nr_vecs /= 2))
2366 bio = bio_alloc(gfp_flags, nr_vecs);
2371 bio->bi_bdev = bdev;
2372 bio->bi_sector = first_sector;
2377 static int submit_one_bio(int rw, struct bio *bio, int mirror_num,
2378 unsigned long bio_flags)
2381 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2382 struct page *page = bvec->bv_page;
2383 struct extent_io_tree *tree = bio->bi_private;
2386 start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
2388 bio->bi_private = NULL;
2392 if (tree->ops && tree->ops->submit_bio_hook)
2393 ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
2394 mirror_num, bio_flags, start);
2396 submit_bio(rw, bio);
2398 if (bio_flagged(bio, BIO_EOPNOTSUPP))
2404 static int submit_extent_page(int rw, struct extent_io_tree *tree,
2405 struct page *page, sector_t sector,
2406 size_t size, unsigned long offset,
2407 struct block_device *bdev,
2408 struct bio **bio_ret,
2409 unsigned long max_pages,
2410 bio_end_io_t end_io_func,
2412 unsigned long prev_bio_flags,
2413 unsigned long bio_flags)
2419 int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
2420 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2421 size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
2423 if (bio_ret && *bio_ret) {
2426 contig = bio->bi_sector == sector;
2428 contig = bio->bi_sector + (bio->bi_size >> 9) ==
2431 if (prev_bio_flags != bio_flags || !contig ||
2432 (tree->ops && tree->ops->merge_bio_hook &&
2433 tree->ops->merge_bio_hook(page, offset, page_size, bio,
2435 bio_add_page(bio, page, page_size, offset) < page_size) {
2436 ret = submit_one_bio(rw, bio, mirror_num,
2443 if (this_compressed)
2446 nr = bio_get_nr_vecs(bdev);
2448 bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
2452 bio_add_page(bio, page, page_size, offset);
2453 bio->bi_end_io = end_io_func;
2454 bio->bi_private = tree;
2459 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
2464 void set_page_extent_mapped(struct page *page)
2466 if (!PagePrivate(page)) {
2467 SetPagePrivate(page);
2468 page_cache_get(page);
2469 set_page_private(page, EXTENT_PAGE_PRIVATE);
2473 static void set_page_extent_head(struct page *page, unsigned long len)
2475 WARN_ON(!PagePrivate(page));
2476 set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
2480 * basic readpage implementation. Locked extent state structs are inserted
2481 * into the tree that are removed when the IO is done (by the end_io
2484 static int __extent_read_full_page(struct extent_io_tree *tree,
2486 get_extent_t *get_extent,
2487 struct bio **bio, int mirror_num,
2488 unsigned long *bio_flags)
2490 struct inode *inode = page->mapping->host;
2491 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2492 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2496 u64 last_byte = i_size_read(inode);
2500 struct extent_map *em;
2501 struct block_device *bdev;
2502 struct btrfs_ordered_extent *ordered;
2505 size_t pg_offset = 0;
2507 size_t disk_io_size;
2508 size_t blocksize = inode->i_sb->s_blocksize;
2509 unsigned long this_bio_flag = 0;
2511 set_page_extent_mapped(page);
2513 if (!PageUptodate(page)) {
2514 if (cleancache_get_page(page) == 0) {
2515 BUG_ON(blocksize != PAGE_SIZE);
2522 lock_extent(tree, start, end, GFP_NOFS);
2523 ordered = btrfs_lookup_ordered_extent(inode, start);
2526 unlock_extent(tree, start, end, GFP_NOFS);
2527 btrfs_start_ordered_extent(inode, ordered, 1);
2528 btrfs_put_ordered_extent(ordered);
2531 if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
2533 size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
2536 iosize = PAGE_CACHE_SIZE - zero_offset;
2537 userpage = kmap_atomic(page, KM_USER0);
2538 memset(userpage + zero_offset, 0, iosize);
2539 flush_dcache_page(page);
2540 kunmap_atomic(userpage, KM_USER0);
2543 while (cur <= end) {
2544 if (cur >= last_byte) {
2546 struct extent_state *cached = NULL;
2548 iosize = PAGE_CACHE_SIZE - pg_offset;
2549 userpage = kmap_atomic(page, KM_USER0);
2550 memset(userpage + pg_offset, 0, iosize);
2551 flush_dcache_page(page);
2552 kunmap_atomic(userpage, KM_USER0);
2553 set_extent_uptodate(tree, cur, cur + iosize - 1,
2555 unlock_extent_cached(tree, cur, cur + iosize - 1,
2559 em = get_extent(inode, page, pg_offset, cur,
2561 if (IS_ERR_OR_NULL(em)) {
2563 unlock_extent(tree, cur, end, GFP_NOFS);
2566 extent_offset = cur - em->start;
2567 BUG_ON(extent_map_end(em) <= cur);
2570 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2571 this_bio_flag = EXTENT_BIO_COMPRESSED;
2572 extent_set_compress_type(&this_bio_flag,
2576 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2577 cur_end = min(extent_map_end(em) - 1, end);
2578 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2579 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2580 disk_io_size = em->block_len;
2581 sector = em->block_start >> 9;
2583 sector = (em->block_start + extent_offset) >> 9;
2584 disk_io_size = iosize;
2587 block_start = em->block_start;
2588 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2589 block_start = EXTENT_MAP_HOLE;
2590 free_extent_map(em);
2593 /* we've found a hole, just zero and go on */
2594 if (block_start == EXTENT_MAP_HOLE) {
2596 struct extent_state *cached = NULL;
2598 userpage = kmap_atomic(page, KM_USER0);
2599 memset(userpage + pg_offset, 0, iosize);
2600 flush_dcache_page(page);
2601 kunmap_atomic(userpage, KM_USER0);
2603 set_extent_uptodate(tree, cur, cur + iosize - 1,
2605 unlock_extent_cached(tree, cur, cur + iosize - 1,
2608 pg_offset += iosize;
2611 /* the get_extent function already copied into the page */
2612 if (test_range_bit(tree, cur, cur_end,
2613 EXTENT_UPTODATE, 1, NULL)) {
2614 check_page_uptodate(tree, page);
2615 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2617 pg_offset += iosize;
2620 /* we have an inline extent but it didn't get marked up
2621 * to date. Error out
2623 if (block_start == EXTENT_MAP_INLINE) {
2625 unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
2627 pg_offset += iosize;
2632 if (tree->ops && tree->ops->readpage_io_hook) {
2633 ret = tree->ops->readpage_io_hook(page, cur,
2637 unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
2639 ret = submit_extent_page(READ, tree, page,
2640 sector, disk_io_size, pg_offset,
2642 end_bio_extent_readpage, mirror_num,
2646 *bio_flags = this_bio_flag;
2651 pg_offset += iosize;
2655 if (!PageError(page))
2656 SetPageUptodate(page);
2662 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
2663 get_extent_t *get_extent, int mirror_num)
2665 struct bio *bio = NULL;
2666 unsigned long bio_flags = 0;
2669 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
2672 ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
2676 static noinline void update_nr_written(struct page *page,
2677 struct writeback_control *wbc,
2678 unsigned long nr_written)
2680 wbc->nr_to_write -= nr_written;
2681 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
2682 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
2683 page->mapping->writeback_index = page->index + nr_written;
2687 * the writepage semantics are similar to regular writepage. extent
2688 * records are inserted to lock ranges in the tree, and as dirty areas
2689 * are found, they are marked writeback. Then the lock bits are removed
2690 * and the end_io handler clears the writeback ranges
2692 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
2695 struct inode *inode = page->mapping->host;
2696 struct extent_page_data *epd = data;
2697 struct extent_io_tree *tree = epd->tree;
2698 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
2700 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2704 u64 last_byte = i_size_read(inode);
2708 struct extent_state *cached_state = NULL;
2709 struct extent_map *em;
2710 struct block_device *bdev;
2713 size_t pg_offset = 0;
2715 loff_t i_size = i_size_read(inode);
2716 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
2722 unsigned long nr_written = 0;
2723 bool fill_delalloc = true;
2725 if (wbc->sync_mode == WB_SYNC_ALL)
2726 write_flags = WRITE_SYNC;
2728 write_flags = WRITE;
2730 trace___extent_writepage(page, inode, wbc);
2732 WARN_ON(!PageLocked(page));
2734 ClearPageError(page);
2736 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
2737 if (page->index > end_index ||
2738 (page->index == end_index && !pg_offset)) {
2739 page->mapping->a_ops->invalidatepage(page, 0);
2744 if (page->index == end_index) {
2747 userpage = kmap_atomic(page, KM_USER0);
2748 memset(userpage + pg_offset, 0,
2749 PAGE_CACHE_SIZE - pg_offset);
2750 kunmap_atomic(userpage, KM_USER0);
2751 flush_dcache_page(page);
2755 set_page_extent_mapped(page);
2757 if (!tree->ops || !tree->ops->fill_delalloc)
2758 fill_delalloc = false;
2760 delalloc_start = start;
2763 if (!epd->extent_locked && fill_delalloc) {
2764 u64 delalloc_to_write = 0;
2766 * make sure the wbc mapping index is at least updated
2769 update_nr_written(page, wbc, 0);
2771 while (delalloc_end < page_end) {
2772 nr_delalloc = find_lock_delalloc_range(inode, tree,
2777 if (nr_delalloc == 0) {
2778 delalloc_start = delalloc_end + 1;
2781 tree->ops->fill_delalloc(inode, page, delalloc_start,
2782 delalloc_end, &page_started,
2785 * delalloc_end is already one less than the total
2786 * length, so we don't subtract one from
2789 delalloc_to_write += (delalloc_end - delalloc_start +
2792 delalloc_start = delalloc_end + 1;
2794 if (wbc->nr_to_write < delalloc_to_write) {
2797 if (delalloc_to_write < thresh * 2)
2798 thresh = delalloc_to_write;
2799 wbc->nr_to_write = min_t(u64, delalloc_to_write,
2803 /* did the fill delalloc function already unlock and start
2809 * we've unlocked the page, so we can't update
2810 * the mapping's writeback index, just update
2813 wbc->nr_to_write -= nr_written;
2817 if (tree->ops && tree->ops->writepage_start_hook) {
2818 ret = tree->ops->writepage_start_hook(page, start,
2820 if (ret == -EAGAIN) {
2821 redirty_page_for_writepage(wbc, page);
2822 update_nr_written(page, wbc, nr_written);
2830 * we don't want to touch the inode after unlocking the page,
2831 * so we update the mapping writeback index now
2833 update_nr_written(page, wbc, nr_written + 1);
2836 if (last_byte <= start) {
2837 if (tree->ops && tree->ops->writepage_end_io_hook)
2838 tree->ops->writepage_end_io_hook(page, start,
2843 blocksize = inode->i_sb->s_blocksize;
2845 while (cur <= end) {
2846 if (cur >= last_byte) {
2847 if (tree->ops && tree->ops->writepage_end_io_hook)
2848 tree->ops->writepage_end_io_hook(page, cur,
2852 em = epd->get_extent(inode, page, pg_offset, cur,
2854 if (IS_ERR_OR_NULL(em)) {
2859 extent_offset = cur - em->start;
2860 BUG_ON(extent_map_end(em) <= cur);
2862 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2863 iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
2864 sector = (em->block_start + extent_offset) >> 9;
2866 block_start = em->block_start;
2867 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
2868 free_extent_map(em);
2872 * compressed and inline extents are written through other
2875 if (compressed || block_start == EXTENT_MAP_HOLE ||
2876 block_start == EXTENT_MAP_INLINE) {
2878 * end_io notification does not happen here for
2879 * compressed extents
2881 if (!compressed && tree->ops &&
2882 tree->ops->writepage_end_io_hook)
2883 tree->ops->writepage_end_io_hook(page, cur,
2886 else if (compressed) {
2887 /* we don't want to end_page_writeback on
2888 * a compressed extent. this happens
2895 pg_offset += iosize;
2898 /* leave this out until we have a page_mkwrite call */
2899 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
2900 EXTENT_DIRTY, 0, NULL)) {
2902 pg_offset += iosize;
2906 if (tree->ops && tree->ops->writepage_io_hook) {
2907 ret = tree->ops->writepage_io_hook(page, cur,
2915 unsigned long max_nr = end_index + 1;
2917 set_range_writeback(tree, cur, cur + iosize - 1);
2918 if (!PageWriteback(page)) {
2919 printk(KERN_ERR "btrfs warning page %lu not "
2920 "writeback, cur %llu end %llu\n",
2921 page->index, (unsigned long long)cur,
2922 (unsigned long long)end);
2925 ret = submit_extent_page(write_flags, tree, page,
2926 sector, iosize, pg_offset,
2927 bdev, &epd->bio, max_nr,
2928 end_bio_extent_writepage,
2934 pg_offset += iosize;
2939 /* make sure the mapping tag for page dirty gets cleared */
2940 set_page_writeback(page);
2941 end_page_writeback(page);
2947 /* drop our reference on any cached states */
2948 free_extent_state(cached_state);
2953 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
2954 * @mapping: address space structure to write
2955 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2956 * @writepage: function called for each page
2957 * @data: data passed to writepage function
2959 * If a page is already under I/O, write_cache_pages() skips it, even
2960 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
2961 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
2962 * and msync() need to guarantee that all the data which was dirty at the time
2963 * the call was made get new I/O started against them. If wbc->sync_mode is
2964 * WB_SYNC_ALL then we were called for data integrity and we must wait for
2965 * existing IO to complete.
2967 static int extent_write_cache_pages(struct extent_io_tree *tree,
2968 struct address_space *mapping,
2969 struct writeback_control *wbc,
2970 writepage_t writepage, void *data,
2971 void (*flush_fn)(void *))
2975 int nr_to_write_done = 0;
2976 struct pagevec pvec;
2979 pgoff_t end; /* Inclusive */
2983 pagevec_init(&pvec, 0);
2984 if (wbc->range_cyclic) {
2985 index = mapping->writeback_index; /* Start from prev offset */
2988 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2989 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2992 if (wbc->sync_mode == WB_SYNC_ALL)
2993 tag = PAGECACHE_TAG_TOWRITE;
2995 tag = PAGECACHE_TAG_DIRTY;
2997 if (wbc->sync_mode == WB_SYNC_ALL)
2998 tag_pages_for_writeback(mapping, index, end);
2999 while (!done && !nr_to_write_done && (index <= end) &&
3000 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3001 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3005 for (i = 0; i < nr_pages; i++) {
3006 struct page *page = pvec.pages[i];
3009 * At this point we hold neither mapping->tree_lock nor
3010 * lock on the page itself: the page may be truncated or
3011 * invalidated (changing page->mapping to NULL), or even
3012 * swizzled back from swapper_space to tmpfs file
3016 tree->ops->write_cache_pages_lock_hook) {
3017 tree->ops->write_cache_pages_lock_hook(page,
3020 if (!trylock_page(page)) {
3026 if (unlikely(page->mapping != mapping)) {
3031 if (!wbc->range_cyclic && page->index > end) {
3037 if (wbc->sync_mode != WB_SYNC_NONE) {
3038 if (PageWriteback(page))
3040 wait_on_page_writeback(page);
3043 if (PageWriteback(page) ||
3044 !clear_page_dirty_for_io(page)) {
3049 ret = (*writepage)(page, wbc, data);
3051 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
3059 * the filesystem may choose to bump up nr_to_write.
3060 * We have to make sure to honor the new nr_to_write
3063 nr_to_write_done = wbc->nr_to_write <= 0;
3065 pagevec_release(&pvec);
3068 if (!scanned && !done) {
3070 * We hit the last page and there is more work to be done: wrap
3071 * back to the start of the file
3080 static void flush_epd_write_bio(struct extent_page_data *epd)
3084 submit_one_bio(WRITE_SYNC, epd->bio, 0, 0);
3086 submit_one_bio(WRITE, epd->bio, 0, 0);
3091 static noinline void flush_write_bio(void *data)
3093 struct extent_page_data *epd = data;
3094 flush_epd_write_bio(epd);
3097 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
3098 get_extent_t *get_extent,
3099 struct writeback_control *wbc)
3102 struct extent_page_data epd = {
3105 .get_extent = get_extent,
3107 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3110 ret = __extent_writepage(page, wbc, &epd);
3112 flush_epd_write_bio(&epd);
3116 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
3117 u64 start, u64 end, get_extent_t *get_extent,
3121 struct address_space *mapping = inode->i_mapping;
3123 unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
3126 struct extent_page_data epd = {
3129 .get_extent = get_extent,
3131 .sync_io = mode == WB_SYNC_ALL,
3133 struct writeback_control wbc_writepages = {
3135 .nr_to_write = nr_pages * 2,
3136 .range_start = start,
3137 .range_end = end + 1,
3140 while (start <= end) {
3141 page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
3142 if (clear_page_dirty_for_io(page))
3143 ret = __extent_writepage(page, &wbc_writepages, &epd);
3145 if (tree->ops && tree->ops->writepage_end_io_hook)
3146 tree->ops->writepage_end_io_hook(page, start,
3147 start + PAGE_CACHE_SIZE - 1,
3151 page_cache_release(page);
3152 start += PAGE_CACHE_SIZE;
3155 flush_epd_write_bio(&epd);
3159 int extent_writepages(struct extent_io_tree *tree,
3160 struct address_space *mapping,
3161 get_extent_t *get_extent,
3162 struct writeback_control *wbc)
3165 struct extent_page_data epd = {
3168 .get_extent = get_extent,
3170 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3173 ret = extent_write_cache_pages(tree, mapping, wbc,
3174 __extent_writepage, &epd,
3176 flush_epd_write_bio(&epd);
3180 int extent_readpages(struct extent_io_tree *tree,
3181 struct address_space *mapping,
3182 struct list_head *pages, unsigned nr_pages,
3183 get_extent_t get_extent)
3185 struct bio *bio = NULL;
3187 unsigned long bio_flags = 0;
3189 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
3190 struct page *page = list_entry(pages->prev, struct page, lru);
3192 prefetchw(&page->flags);
3193 list_del(&page->lru);
3194 if (!add_to_page_cache_lru(page, mapping,
3195 page->index, GFP_NOFS)) {
3196 __extent_read_full_page(tree, page, get_extent,
3197 &bio, 0, &bio_flags);
3199 page_cache_release(page);
3201 BUG_ON(!list_empty(pages));
3203 submit_one_bio(READ, bio, 0, bio_flags);
3208 * basic invalidatepage code, this waits on any locked or writeback
3209 * ranges corresponding to the page, and then deletes any extent state
3210 * records from the tree
3212 int extent_invalidatepage(struct extent_io_tree *tree,
3213 struct page *page, unsigned long offset)
3215 struct extent_state *cached_state = NULL;
3216 u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
3217 u64 end = start + PAGE_CACHE_SIZE - 1;
3218 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
3220 start += (offset + blocksize - 1) & ~(blocksize - 1);
3224 lock_extent_bits(tree, start, end, 0, &cached_state, GFP_NOFS);
3225 wait_on_page_writeback(page);
3226 clear_extent_bit(tree, start, end,
3227 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
3228 EXTENT_DO_ACCOUNTING,
3229 1, 1, &cached_state, GFP_NOFS);
3234 * a helper for releasepage, this tests for areas of the page that
3235 * are locked or under IO and drops the related state bits if it is safe
3238 int try_release_extent_state(struct extent_map_tree *map,
3239 struct extent_io_tree *tree, struct page *page,
3242 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
3243 u64 end = start + PAGE_CACHE_SIZE - 1;
3246 if (test_range_bit(tree, start, end,
3247 EXTENT_IOBITS, 0, NULL))
3250 if ((mask & GFP_NOFS) == GFP_NOFS)
3253 * at this point we can safely clear everything except the
3254 * locked bit and the nodatasum bit
3256 ret = clear_extent_bit(tree, start, end,
3257 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
3260 /* if clear_extent_bit failed for enomem reasons,
3261 * we can't allow the release to continue.
3272 * a helper for releasepage. As long as there are no locked extents
3273 * in the range corresponding to the page, both state records and extent
3274 * map records are removed
3276 int try_release_extent_mapping(struct extent_map_tree *map,
3277 struct extent_io_tree *tree, struct page *page,
3280 struct extent_map *em;
3281 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
3282 u64 end = start + PAGE_CACHE_SIZE - 1;
3284 if ((mask & __GFP_WAIT) &&
3285 page->mapping->host->i_size > 16 * 1024 * 1024) {
3287 while (start <= end) {
3288 len = end - start + 1;
3289 write_lock(&map->lock);
3290 em = lookup_extent_mapping(map, start, len);
3291 if (IS_ERR_OR_NULL(em)) {
3292 write_unlock(&map->lock);
3295 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
3296 em->start != start) {
3297 write_unlock(&map->lock);
3298 free_extent_map(em);
3301 if (!test_range_bit(tree, em->start,
3302 extent_map_end(em) - 1,
3303 EXTENT_LOCKED | EXTENT_WRITEBACK,
3305 remove_extent_mapping(map, em);
3306 /* once for the rb tree */
3307 free_extent_map(em);
3309 start = extent_map_end(em);
3310 write_unlock(&map->lock);
3313 free_extent_map(em);
3316 return try_release_extent_state(map, tree, page, mask);
3320 * helper function for fiemap, which doesn't want to see any holes.
3321 * This maps until we find something past 'last'
3323 static struct extent_map *get_extent_skip_holes(struct inode *inode,
3326 get_extent_t *get_extent)
3328 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
3329 struct extent_map *em;
3336 len = last - offset;
3339 len = (len + sectorsize - 1) & ~(sectorsize - 1);
3340 em = get_extent(inode, NULL, 0, offset, len, 0);
3341 if (IS_ERR_OR_NULL(em))
3344 /* if this isn't a hole return it */
3345 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
3346 em->block_start != EXTENT_MAP_HOLE) {
3350 /* this is a hole, advance to the next extent */
3351 offset = extent_map_end(em);
3352 free_extent_map(em);
3359 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3360 __u64 start, __u64 len, get_extent_t *get_extent)
3364 u64 max = start + len;
3368 u64 last_for_get_extent = 0;
3370 u64 isize = i_size_read(inode);
3371 struct btrfs_key found_key;
3372 struct extent_map *em = NULL;
3373 struct extent_state *cached_state = NULL;
3374 struct btrfs_path *path;
3375 struct btrfs_file_extent_item *item;
3380 unsigned long emflags;
3385 path = btrfs_alloc_path();
3388 path->leave_spinning = 1;
3390 start = ALIGN(start, BTRFS_I(inode)->root->sectorsize);
3391 len = ALIGN(len, BTRFS_I(inode)->root->sectorsize);
3394 * lookup the last file extent. We're not using i_size here
3395 * because there might be preallocation past i_size
3397 ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
3398 path, btrfs_ino(inode), -1, 0);
3400 btrfs_free_path(path);
3405 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3406 struct btrfs_file_extent_item);
3407 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
3408 found_type = btrfs_key_type(&found_key);
3410 /* No extents, but there might be delalloc bits */
3411 if (found_key.objectid != btrfs_ino(inode) ||
3412 found_type != BTRFS_EXTENT_DATA_KEY) {
3413 /* have to trust i_size as the end */
3415 last_for_get_extent = isize;
3418 * remember the start of the last extent. There are a
3419 * bunch of different factors that go into the length of the
3420 * extent, so its much less complex to remember where it started
3422 last = found_key.offset;
3423 last_for_get_extent = last + 1;
3425 btrfs_free_path(path);
3428 * we might have some extents allocated but more delalloc past those
3429 * extents. so, we trust isize unless the start of the last extent is
3434 last_for_get_extent = isize;
3437 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
3438 &cached_state, GFP_NOFS);
3440 em = get_extent_skip_holes(inode, start, last_for_get_extent,
3450 u64 offset_in_extent;
3452 /* break if the extent we found is outside the range */
3453 if (em->start >= max || extent_map_end(em) < off)
3457 * get_extent may return an extent that starts before our
3458 * requested range. We have to make sure the ranges
3459 * we return to fiemap always move forward and don't
3460 * overlap, so adjust the offsets here
3462 em_start = max(em->start, off);
3465 * record the offset from the start of the extent
3466 * for adjusting the disk offset below
3468 offset_in_extent = em_start - em->start;
3469 em_end = extent_map_end(em);
3470 em_len = em_end - em_start;
3471 emflags = em->flags;
3476 * bump off for our next call to get_extent
3478 off = extent_map_end(em);
3482 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
3484 flags |= FIEMAP_EXTENT_LAST;
3485 } else if (em->block_start == EXTENT_MAP_INLINE) {
3486 flags |= (FIEMAP_EXTENT_DATA_INLINE |
3487 FIEMAP_EXTENT_NOT_ALIGNED);
3488 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
3489 flags |= (FIEMAP_EXTENT_DELALLOC |
3490 FIEMAP_EXTENT_UNKNOWN);
3492 disko = em->block_start + offset_in_extent;
3494 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
3495 flags |= FIEMAP_EXTENT_ENCODED;
3497 free_extent_map(em);
3499 if ((em_start >= last) || em_len == (u64)-1 ||
3500 (last == (u64)-1 && isize <= em_end)) {
3501 flags |= FIEMAP_EXTENT_LAST;
3505 /* now scan forward to see if this is really the last extent. */
3506 em = get_extent_skip_holes(inode, off, last_for_get_extent,
3513 flags |= FIEMAP_EXTENT_LAST;
3516 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
3522 free_extent_map(em);
3524 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len,
3525 &cached_state, GFP_NOFS);
3529 inline struct page *extent_buffer_page(struct extent_buffer *eb,
3533 struct address_space *mapping;
3536 return eb->first_page;
3537 i += eb->start >> PAGE_CACHE_SHIFT;
3538 mapping = eb->first_page->mapping;
3543 * extent_buffer_page is only called after pinning the page
3544 * by increasing the reference count. So we know the page must
3545 * be in the radix tree.
3548 p = radix_tree_lookup(&mapping->page_tree, i);
3554 inline unsigned long num_extent_pages(u64 start, u64 len)
3556 return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
3557 (start >> PAGE_CACHE_SHIFT);
3560 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
3565 struct extent_buffer *eb = NULL;
3567 unsigned long flags;
3570 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
3575 rwlock_init(&eb->lock);
3576 atomic_set(&eb->write_locks, 0);
3577 atomic_set(&eb->read_locks, 0);
3578 atomic_set(&eb->blocking_readers, 0);
3579 atomic_set(&eb->blocking_writers, 0);
3580 atomic_set(&eb->spinning_readers, 0);
3581 atomic_set(&eb->spinning_writers, 0);
3582 init_waitqueue_head(&eb->write_lock_wq);
3583 init_waitqueue_head(&eb->read_lock_wq);
3586 spin_lock_irqsave(&leak_lock, flags);
3587 list_add(&eb->leak_list, &buffers);
3588 spin_unlock_irqrestore(&leak_lock, flags);
3590 atomic_set(&eb->refs, 1);
3595 static void __free_extent_buffer(struct extent_buffer *eb)
3598 unsigned long flags;
3599 spin_lock_irqsave(&leak_lock, flags);
3600 list_del(&eb->leak_list);
3601 spin_unlock_irqrestore(&leak_lock, flags);
3603 kmem_cache_free(extent_buffer_cache, eb);
3607 * Helper for releasing extent buffer page.
3609 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
3610 unsigned long start_idx)
3612 unsigned long index;
3615 if (!eb->first_page)
3618 index = num_extent_pages(eb->start, eb->len);
3619 if (start_idx >= index)
3624 page = extent_buffer_page(eb, index);
3626 page_cache_release(page);
3627 } while (index != start_idx);
3631 * Helper for releasing the extent buffer.
3633 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
3635 btrfs_release_extent_buffer_page(eb, 0);
3636 __free_extent_buffer(eb);
3639 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
3640 u64 start, unsigned long len,
3643 unsigned long num_pages = num_extent_pages(start, len);
3645 unsigned long index = start >> PAGE_CACHE_SHIFT;
3646 struct extent_buffer *eb;
3647 struct extent_buffer *exists = NULL;
3649 struct address_space *mapping = tree->mapping;
3654 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3655 if (eb && atomic_inc_not_zero(&eb->refs)) {
3657 mark_page_accessed(eb->first_page);
3662 eb = __alloc_extent_buffer(tree, start, len, GFP_NOFS);
3667 eb->first_page = page0;
3670 page_cache_get(page0);
3671 mark_page_accessed(page0);
3672 set_page_extent_mapped(page0);
3673 set_page_extent_head(page0, len);
3674 uptodate = PageUptodate(page0);
3678 for (; i < num_pages; i++, index++) {
3679 p = find_or_create_page(mapping, index, GFP_NOFS);
3684 set_page_extent_mapped(p);
3685 mark_page_accessed(p);
3688 set_page_extent_head(p, len);
3690 set_page_private(p, EXTENT_PAGE_PRIVATE);
3692 if (!PageUptodate(p))
3696 * see below about how we avoid a nasty race with release page
3697 * and why we unlock later
3703 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3705 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
3709 spin_lock(&tree->buffer_lock);
3710 ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
3711 if (ret == -EEXIST) {
3712 exists = radix_tree_lookup(&tree->buffer,
3713 start >> PAGE_CACHE_SHIFT);
3714 /* add one reference for the caller */
3715 atomic_inc(&exists->refs);
3716 spin_unlock(&tree->buffer_lock);
3717 radix_tree_preload_end();
3720 /* add one reference for the tree */
3721 atomic_inc(&eb->refs);
3722 spin_unlock(&tree->buffer_lock);
3723 radix_tree_preload_end();
3726 * there is a race where release page may have
3727 * tried to find this extent buffer in the radix
3728 * but failed. It will tell the VM it is safe to
3729 * reclaim the, and it will clear the page private bit.
3730 * We must make sure to set the page private bit properly
3731 * after the extent buffer is in the radix tree so
3732 * it doesn't get lost
3734 set_page_extent_mapped(eb->first_page);
3735 set_page_extent_head(eb->first_page, eb->len);
3737 unlock_page(eb->first_page);
3741 if (eb->first_page && !page0)
3742 unlock_page(eb->first_page);
3744 if (!atomic_dec_and_test(&eb->refs))
3746 btrfs_release_extent_buffer(eb);
3750 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
3751 u64 start, unsigned long len)
3753 struct extent_buffer *eb;
3756 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
3757 if (eb && atomic_inc_not_zero(&eb->refs)) {
3759 mark_page_accessed(eb->first_page);
3767 void free_extent_buffer(struct extent_buffer *eb)
3772 if (!atomic_dec_and_test(&eb->refs))
3778 int clear_extent_buffer_dirty(struct extent_io_tree *tree,
3779 struct extent_buffer *eb)
3782 unsigned long num_pages;
3785 num_pages = num_extent_pages(eb->start, eb->len);
3787 for (i = 0; i < num_pages; i++) {
3788 page = extent_buffer_page(eb, i);
3789 if (!PageDirty(page))
3793 WARN_ON(!PagePrivate(page));
3795 set_page_extent_mapped(page);
3797 set_page_extent_head(page, eb->len);
3799 clear_page_dirty_for_io(page);
3800 spin_lock_irq(&page->mapping->tree_lock);
3801 if (!PageDirty(page)) {
3802 radix_tree_tag_clear(&page->mapping->page_tree,
3804 PAGECACHE_TAG_DIRTY);
3806 spin_unlock_irq(&page->mapping->tree_lock);
3807 ClearPageError(page);
3813 int set_extent_buffer_dirty(struct extent_io_tree *tree,
3814 struct extent_buffer *eb)
3817 unsigned long num_pages;
3820 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
3821 num_pages = num_extent_pages(eb->start, eb->len);
3822 for (i = 0; i < num_pages; i++)
3823 __set_page_dirty_nobuffers(extent_buffer_page(eb, i));
3827 static int __eb_straddles_pages(u64 start, u64 len)
3829 if (len < PAGE_CACHE_SIZE)
3831 if (start & (PAGE_CACHE_SIZE - 1))
3833 if ((start + len) & (PAGE_CACHE_SIZE - 1))
3838 static int eb_straddles_pages(struct extent_buffer *eb)
3840 return __eb_straddles_pages(eb->start, eb->len);
3843 int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
3844 struct extent_buffer *eb,
3845 struct extent_state **cached_state)
3849 unsigned long num_pages;
3851 num_pages = num_extent_pages(eb->start, eb->len);
3852 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
3854 if (eb_straddles_pages(eb)) {
3855 clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3856 cached_state, GFP_NOFS);
3858 for (i = 0; i < num_pages; i++) {
3859 page = extent_buffer_page(eb, i);
3861 ClearPageUptodate(page);
3866 int set_extent_buffer_uptodate(struct extent_io_tree *tree,
3867 struct extent_buffer *eb)
3871 unsigned long num_pages;
3873 num_pages = num_extent_pages(eb->start, eb->len);
3875 if (eb_straddles_pages(eb)) {
3876 set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
3879 for (i = 0; i < num_pages; i++) {
3880 page = extent_buffer_page(eb, i);
3881 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
3882 ((i == num_pages - 1) &&
3883 ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
3884 check_page_uptodate(tree, page);
3887 SetPageUptodate(page);
3892 int extent_range_uptodate(struct extent_io_tree *tree,
3897 int pg_uptodate = 1;
3899 unsigned long index;
3901 if (__eb_straddles_pages(start, end - start + 1)) {
3902 ret = test_range_bit(tree, start, end,
3903 EXTENT_UPTODATE, 1, NULL);
3907 while (start <= end) {
3908 index = start >> PAGE_CACHE_SHIFT;
3909 page = find_get_page(tree->mapping, index);
3910 uptodate = PageUptodate(page);
3911 page_cache_release(page);
3916 start += PAGE_CACHE_SIZE;
3921 int extent_buffer_uptodate(struct extent_io_tree *tree,
3922 struct extent_buffer *eb,
3923 struct extent_state *cached_state)
3926 unsigned long num_pages;
3929 int pg_uptodate = 1;
3931 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3934 if (eb_straddles_pages(eb)) {
3935 ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3936 EXTENT_UPTODATE, 1, cached_state);
3941 num_pages = num_extent_pages(eb->start, eb->len);
3942 for (i = 0; i < num_pages; i++) {
3943 page = extent_buffer_page(eb, i);
3944 if (!PageUptodate(page)) {
3952 int read_extent_buffer_pages(struct extent_io_tree *tree,
3953 struct extent_buffer *eb, u64 start, int wait,
3954 get_extent_t *get_extent, int mirror_num)
3957 unsigned long start_i;
3961 int locked_pages = 0;
3962 int all_uptodate = 1;
3963 int inc_all_pages = 0;
3964 unsigned long num_pages;
3965 struct bio *bio = NULL;
3966 unsigned long bio_flags = 0;
3968 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
3971 if (eb_straddles_pages(eb)) {
3972 if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
3973 EXTENT_UPTODATE, 1, NULL)) {
3979 WARN_ON(start < eb->start);
3980 start_i = (start >> PAGE_CACHE_SHIFT) -
3981 (eb->start >> PAGE_CACHE_SHIFT);
3986 num_pages = num_extent_pages(eb->start, eb->len);
3987 for (i = start_i; i < num_pages; i++) {
3988 page = extent_buffer_page(eb, i);
3989 if (wait == WAIT_NONE) {
3990 if (!trylock_page(page))
3996 if (!PageUptodate(page))
4001 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4005 for (i = start_i; i < num_pages; i++) {
4006 page = extent_buffer_page(eb, i);
4008 WARN_ON(!PagePrivate(page));
4010 set_page_extent_mapped(page);
4012 set_page_extent_head(page, eb->len);
4015 page_cache_get(page);
4016 if (!PageUptodate(page)) {
4019 ClearPageError(page);
4020 err = __extent_read_full_page(tree, page,
4022 mirror_num, &bio_flags);
4031 submit_one_bio(READ, bio, mirror_num, bio_flags);
4033 if (ret || wait != WAIT_COMPLETE)
4036 for (i = start_i; i < num_pages; i++) {
4037 page = extent_buffer_page(eb, i);
4038 wait_on_page_locked(page);
4039 if (!PageUptodate(page))
4044 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4049 while (locked_pages > 0) {
4050 page = extent_buffer_page(eb, i);
4058 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
4059 unsigned long start,
4066 char *dst = (char *)dstv;
4067 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4068 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4070 WARN_ON(start > eb->len);
4071 WARN_ON(start + len > eb->start + eb->len);
4073 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4076 page = extent_buffer_page(eb, i);
4078 cur = min(len, (PAGE_CACHE_SIZE - offset));
4079 kaddr = page_address(page);
4080 memcpy(dst, kaddr + offset, cur);
4089 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
4090 unsigned long min_len, char **map,
4091 unsigned long *map_start,
4092 unsigned long *map_len)
4094 size_t offset = start & (PAGE_CACHE_SIZE - 1);
4097 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4098 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4099 unsigned long end_i = (start_offset + start + min_len - 1) >>
4106 offset = start_offset;
4110 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
4113 if (start + min_len > eb->len) {
4114 printk(KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
4115 "wanted %lu %lu\n", (unsigned long long)eb->start,
4116 eb->len, start, min_len);
4121 p = extent_buffer_page(eb, i);
4122 kaddr = page_address(p);
4123 *map = kaddr + offset;
4124 *map_len = PAGE_CACHE_SIZE - offset;
4128 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
4129 unsigned long start,
4136 char *ptr = (char *)ptrv;
4137 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4138 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4141 WARN_ON(start > eb->len);
4142 WARN_ON(start + len > eb->start + eb->len);
4144 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4147 page = extent_buffer_page(eb, i);
4149 cur = min(len, (PAGE_CACHE_SIZE - offset));
4151 kaddr = page_address(page);
4152 ret = memcmp(ptr, kaddr + offset, cur);
4164 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
4165 unsigned long start, unsigned long len)
4171 char *src = (char *)srcv;
4172 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4173 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4175 WARN_ON(start > eb->len);
4176 WARN_ON(start + len > eb->start + eb->len);
4178 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4181 page = extent_buffer_page(eb, i);
4182 WARN_ON(!PageUptodate(page));
4184 cur = min(len, PAGE_CACHE_SIZE - offset);
4185 kaddr = page_address(page);
4186 memcpy(kaddr + offset, src, cur);
4195 void memset_extent_buffer(struct extent_buffer *eb, char c,
4196 unsigned long start, unsigned long len)
4202 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4203 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4205 WARN_ON(start > eb->len);
4206 WARN_ON(start + len > eb->start + eb->len);
4208 offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
4211 page = extent_buffer_page(eb, i);
4212 WARN_ON(!PageUptodate(page));
4214 cur = min(len, PAGE_CACHE_SIZE - offset);
4215 kaddr = page_address(page);
4216 memset(kaddr + offset, c, cur);
4224 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
4225 unsigned long dst_offset, unsigned long src_offset,
4228 u64 dst_len = dst->len;
4233 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4234 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4236 WARN_ON(src->len != dst_len);
4238 offset = (start_offset + dst_offset) &
4239 ((unsigned long)PAGE_CACHE_SIZE - 1);
4242 page = extent_buffer_page(dst, i);
4243 WARN_ON(!PageUptodate(page));
4245 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
4247 kaddr = page_address(page);
4248 read_extent_buffer(src, kaddr + offset, src_offset, cur);
4257 static void move_pages(struct page *dst_page, struct page *src_page,
4258 unsigned long dst_off, unsigned long src_off,
4261 char *dst_kaddr = page_address(dst_page);
4262 if (dst_page == src_page) {
4263 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
4265 char *src_kaddr = page_address(src_page);
4266 char *p = dst_kaddr + dst_off + len;
4267 char *s = src_kaddr + src_off + len;
4274 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
4276 unsigned long distance = (src > dst) ? src - dst : dst - src;
4277 return distance < len;
4280 static void copy_pages(struct page *dst_page, struct page *src_page,
4281 unsigned long dst_off, unsigned long src_off,
4284 char *dst_kaddr = page_address(dst_page);
4287 if (dst_page != src_page) {
4288 src_kaddr = page_address(src_page);
4290 src_kaddr = dst_kaddr;
4291 BUG_ON(areas_overlap(src_off, dst_off, len));
4294 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
4297 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
4298 unsigned long src_offset, unsigned long len)
4301 size_t dst_off_in_page;
4302 size_t src_off_in_page;
4303 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4304 unsigned long dst_i;
4305 unsigned long src_i;
4307 if (src_offset + len > dst->len) {
4308 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4309 "len %lu dst len %lu\n", src_offset, len, dst->len);
4312 if (dst_offset + len > dst->len) {
4313 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4314 "len %lu dst len %lu\n", dst_offset, len, dst->len);
4319 dst_off_in_page = (start_offset + dst_offset) &
4320 ((unsigned long)PAGE_CACHE_SIZE - 1);
4321 src_off_in_page = (start_offset + src_offset) &
4322 ((unsigned long)PAGE_CACHE_SIZE - 1);
4324 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
4325 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
4327 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
4329 cur = min_t(unsigned long, cur,
4330 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
4332 copy_pages(extent_buffer_page(dst, dst_i),
4333 extent_buffer_page(dst, src_i),
4334 dst_off_in_page, src_off_in_page, cur);
4342 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
4343 unsigned long src_offset, unsigned long len)
4346 size_t dst_off_in_page;
4347 size_t src_off_in_page;
4348 unsigned long dst_end = dst_offset + len - 1;
4349 unsigned long src_end = src_offset + len - 1;
4350 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
4351 unsigned long dst_i;
4352 unsigned long src_i;
4354 if (src_offset + len > dst->len) {
4355 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
4356 "len %lu len %lu\n", src_offset, len, dst->len);
4359 if (dst_offset + len > dst->len) {
4360 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
4361 "len %lu len %lu\n", dst_offset, len, dst->len);
4364 if (!areas_overlap(src_offset, dst_offset, len)) {
4365 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
4369 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
4370 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
4372 dst_off_in_page = (start_offset + dst_end) &
4373 ((unsigned long)PAGE_CACHE_SIZE - 1);
4374 src_off_in_page = (start_offset + src_end) &
4375 ((unsigned long)PAGE_CACHE_SIZE - 1);
4377 cur = min_t(unsigned long, len, src_off_in_page + 1);
4378 cur = min(cur, dst_off_in_page + 1);
4379 move_pages(extent_buffer_page(dst, dst_i),
4380 extent_buffer_page(dst, src_i),
4381 dst_off_in_page - cur + 1,
4382 src_off_in_page - cur + 1, cur);
4390 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
4392 struct extent_buffer *eb =
4393 container_of(head, struct extent_buffer, rcu_head);
4395 btrfs_release_extent_buffer(eb);
4398 int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
4400 u64 start = page_offset(page);
4401 struct extent_buffer *eb;
4404 spin_lock(&tree->buffer_lock);
4405 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4407 spin_unlock(&tree->buffer_lock);
4411 if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
4417 * set @eb->refs to 0 if it is already 1, and then release the @eb.
4420 if (atomic_cmpxchg(&eb->refs, 1, 0) != 1) {
4425 radix_tree_delete(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4427 spin_unlock(&tree->buffer_lock);
4429 /* at this point we can safely release the extent buffer */
4430 if (atomic_read(&eb->refs) == 0)
4431 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);