1 #include <linux/bitops.h>
2 #include <linux/slab.h>
5 #include <linux/pagemap.h>
6 #include <linux/page-flags.h>
7 #include <linux/spinlock.h>
8 #include <linux/blkdev.h>
9 #include <linux/swap.h>
10 #include <linux/writeback.h>
11 #include <linux/pagevec.h>
12 #include <linux/prefetch.h>
13 #include <linux/cleancache.h>
14 #include "extent_io.h"
15 #include "extent_map.h"
18 #include "btrfs_inode.h"
20 #include "check-integrity.h"
22 #include "rcu-string.h"
24 static struct kmem_cache *extent_state_cache;
25 static struct kmem_cache *extent_buffer_cache;
26 static struct bio_set *btrfs_bioset;
28 #ifdef CONFIG_BTRFS_DEBUG
29 static LIST_HEAD(buffers);
30 static LIST_HEAD(states);
32 static DEFINE_SPINLOCK(leak_lock);
35 void btrfs_leak_debug_add(struct list_head *new, struct list_head *head)
39 spin_lock_irqsave(&leak_lock, flags);
41 spin_unlock_irqrestore(&leak_lock, flags);
45 void btrfs_leak_debug_del(struct list_head *entry)
49 spin_lock_irqsave(&leak_lock, flags);
51 spin_unlock_irqrestore(&leak_lock, flags);
55 void btrfs_leak_debug_check(void)
57 struct extent_state *state;
58 struct extent_buffer *eb;
60 while (!list_empty(&states)) {
61 state = list_entry(states.next, struct extent_state, leak_list);
62 printk(KERN_ERR "btrfs state leak: start %llu end %llu "
63 "state %lu in tree %p refs %d\n",
64 state->start, state->end, state->state, state->tree,
65 atomic_read(&state->refs));
66 list_del(&state->leak_list);
67 kmem_cache_free(extent_state_cache, state);
70 while (!list_empty(&buffers)) {
71 eb = list_entry(buffers.next, struct extent_buffer, leak_list);
72 printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
74 eb->start, eb->len, atomic_read(&eb->refs));
75 list_del(&eb->leak_list);
76 kmem_cache_free(extent_buffer_cache, eb);
80 #define btrfs_debug_check_extent_io_range(inode, start, end) \
81 __btrfs_debug_check_extent_io_range(__func__, (inode), (start), (end))
82 static inline void __btrfs_debug_check_extent_io_range(const char *caller,
83 struct inode *inode, u64 start, u64 end)
85 u64 isize = i_size_read(inode);
87 if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
88 printk_ratelimited(KERN_DEBUG
89 "btrfs: %s: ino %llu isize %llu odd range [%llu,%llu]\n",
90 caller, btrfs_ino(inode), isize, start, end);
94 #define btrfs_leak_debug_add(new, head) do {} while (0)
95 #define btrfs_leak_debug_del(entry) do {} while (0)
96 #define btrfs_leak_debug_check() do {} while (0)
97 #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
100 #define BUFFER_LRU_MAX 64
105 struct rb_node rb_node;
108 struct extent_page_data {
110 struct extent_io_tree *tree;
111 get_extent_t *get_extent;
112 unsigned long bio_flags;
114 /* tells writepage not to lock the state bits for this range
115 * it still does the unlocking
117 unsigned int extent_locked:1;
119 /* tells the submit_bio code to use a WRITE_SYNC */
120 unsigned int sync_io:1;
123 static noinline void flush_write_bio(void *data);
124 static inline struct btrfs_fs_info *
125 tree_fs_info(struct extent_io_tree *tree)
127 return btrfs_sb(tree->mapping->host->i_sb);
130 int __init extent_io_init(void)
132 extent_state_cache = kmem_cache_create("btrfs_extent_state",
133 sizeof(struct extent_state), 0,
134 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
135 if (!extent_state_cache)
138 extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
139 sizeof(struct extent_buffer), 0,
140 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
141 if (!extent_buffer_cache)
142 goto free_state_cache;
144 btrfs_bioset = bioset_create(BIO_POOL_SIZE,
145 offsetof(struct btrfs_io_bio, bio));
147 goto free_buffer_cache;
151 kmem_cache_destroy(extent_buffer_cache);
152 extent_buffer_cache = NULL;
155 kmem_cache_destroy(extent_state_cache);
156 extent_state_cache = NULL;
160 void extent_io_exit(void)
162 btrfs_leak_debug_check();
165 * Make sure all delayed rcu free are flushed before we
169 if (extent_state_cache)
170 kmem_cache_destroy(extent_state_cache);
171 if (extent_buffer_cache)
172 kmem_cache_destroy(extent_buffer_cache);
174 bioset_free(btrfs_bioset);
177 void extent_io_tree_init(struct extent_io_tree *tree,
178 struct address_space *mapping)
180 tree->state = RB_ROOT;
181 INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
183 tree->dirty_bytes = 0;
184 spin_lock_init(&tree->lock);
185 spin_lock_init(&tree->buffer_lock);
186 tree->mapping = mapping;
189 static struct extent_state *alloc_extent_state(gfp_t mask)
191 struct extent_state *state;
193 state = kmem_cache_alloc(extent_state_cache, mask);
199 btrfs_leak_debug_add(&state->leak_list, &states);
200 atomic_set(&state->refs, 1);
201 init_waitqueue_head(&state->wq);
202 trace_alloc_extent_state(state, mask, _RET_IP_);
206 void free_extent_state(struct extent_state *state)
210 if (atomic_dec_and_test(&state->refs)) {
211 WARN_ON(state->tree);
212 btrfs_leak_debug_del(&state->leak_list);
213 trace_free_extent_state(state, _RET_IP_);
214 kmem_cache_free(extent_state_cache, state);
218 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
219 struct rb_node *node)
221 struct rb_node **p = &root->rb_node;
222 struct rb_node *parent = NULL;
223 struct tree_entry *entry;
227 entry = rb_entry(parent, struct tree_entry, rb_node);
229 if (offset < entry->start)
231 else if (offset > entry->end)
237 rb_link_node(node, parent, p);
238 rb_insert_color(node, root);
242 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
243 struct rb_node **prev_ret,
244 struct rb_node **next_ret)
246 struct rb_root *root = &tree->state;
247 struct rb_node *n = root->rb_node;
248 struct rb_node *prev = NULL;
249 struct rb_node *orig_prev = NULL;
250 struct tree_entry *entry;
251 struct tree_entry *prev_entry = NULL;
254 entry = rb_entry(n, struct tree_entry, rb_node);
258 if (offset < entry->start)
260 else if (offset > entry->end)
268 while (prev && offset > prev_entry->end) {
269 prev = rb_next(prev);
270 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
277 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
278 while (prev && offset < prev_entry->start) {
279 prev = rb_prev(prev);
280 prev_entry = rb_entry(prev, struct tree_entry, rb_node);
287 static inline struct rb_node *tree_search(struct extent_io_tree *tree,
290 struct rb_node *prev = NULL;
293 ret = __etree_search(tree, offset, &prev, NULL);
299 static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
300 struct extent_state *other)
302 if (tree->ops && tree->ops->merge_extent_hook)
303 tree->ops->merge_extent_hook(tree->mapping->host, new,
308 * utility function to look for merge candidates inside a given range.
309 * Any extents with matching state are merged together into a single
310 * extent in the tree. Extents with EXTENT_IO in their state field
311 * are not merged because the end_io handlers need to be able to do
312 * operations on them without sleeping (or doing allocations/splits).
314 * This should be called with the tree lock held.
316 static void merge_state(struct extent_io_tree *tree,
317 struct extent_state *state)
319 struct extent_state *other;
320 struct rb_node *other_node;
322 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
325 other_node = rb_prev(&state->rb_node);
327 other = rb_entry(other_node, struct extent_state, rb_node);
328 if (other->end == state->start - 1 &&
329 other->state == state->state) {
330 merge_cb(tree, state, other);
331 state->start = other->start;
333 rb_erase(&other->rb_node, &tree->state);
334 free_extent_state(other);
337 other_node = rb_next(&state->rb_node);
339 other = rb_entry(other_node, struct extent_state, rb_node);
340 if (other->start == state->end + 1 &&
341 other->state == state->state) {
342 merge_cb(tree, state, other);
343 state->end = other->end;
345 rb_erase(&other->rb_node, &tree->state);
346 free_extent_state(other);
351 static void set_state_cb(struct extent_io_tree *tree,
352 struct extent_state *state, unsigned long *bits)
354 if (tree->ops && tree->ops->set_bit_hook)
355 tree->ops->set_bit_hook(tree->mapping->host, state, bits);
358 static void clear_state_cb(struct extent_io_tree *tree,
359 struct extent_state *state, unsigned long *bits)
361 if (tree->ops && tree->ops->clear_bit_hook)
362 tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
365 static void set_state_bits(struct extent_io_tree *tree,
366 struct extent_state *state, unsigned long *bits);
369 * insert an extent_state struct into the tree. 'bits' are set on the
370 * struct before it is inserted.
372 * This may return -EEXIST if the extent is already there, in which case the
373 * state struct is freed.
375 * The tree lock is not taken internally. This is a utility function and
376 * probably isn't what you want to call (see set/clear_extent_bit).
378 static int insert_state(struct extent_io_tree *tree,
379 struct extent_state *state, u64 start, u64 end,
382 struct rb_node *node;
385 WARN(1, KERN_ERR "btrfs end < start %llu %llu\n",
387 state->start = start;
390 set_state_bits(tree, state, bits);
392 node = tree_insert(&tree->state, end, &state->rb_node);
394 struct extent_state *found;
395 found = rb_entry(node, struct extent_state, rb_node);
396 printk(KERN_ERR "btrfs found node %llu %llu on insert of "
398 found->start, found->end, start, end);
402 merge_state(tree, state);
406 static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
409 if (tree->ops && tree->ops->split_extent_hook)
410 tree->ops->split_extent_hook(tree->mapping->host, orig, split);
414 * split a given extent state struct in two, inserting the preallocated
415 * struct 'prealloc' as the newly created second half. 'split' indicates an
416 * offset inside 'orig' where it should be split.
419 * the tree has 'orig' at [orig->start, orig->end]. After calling, there
420 * are two extent state structs in the tree:
421 * prealloc: [orig->start, split - 1]
422 * orig: [ split, orig->end ]
424 * The tree locks are not taken by this function. They need to be held
427 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
428 struct extent_state *prealloc, u64 split)
430 struct rb_node *node;
432 split_cb(tree, orig, split);
434 prealloc->start = orig->start;
435 prealloc->end = split - 1;
436 prealloc->state = orig->state;
439 node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
441 free_extent_state(prealloc);
444 prealloc->tree = tree;
448 static struct extent_state *next_state(struct extent_state *state)
450 struct rb_node *next = rb_next(&state->rb_node);
452 return rb_entry(next, struct extent_state, rb_node);
458 * utility function to clear some bits in an extent state struct.
459 * it will optionally wake up any one waiting on this state (wake == 1).
461 * If no bits are set on the state struct after clearing things, the
462 * struct is freed and removed from the tree
464 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
465 struct extent_state *state,
466 unsigned long *bits, int wake)
468 struct extent_state *next;
469 unsigned long bits_to_clear = *bits & ~EXTENT_CTLBITS;
471 if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
472 u64 range = state->end - state->start + 1;
473 WARN_ON(range > tree->dirty_bytes);
474 tree->dirty_bytes -= range;
476 clear_state_cb(tree, state, bits);
477 state->state &= ~bits_to_clear;
480 if (state->state == 0) {
481 next = next_state(state);
483 rb_erase(&state->rb_node, &tree->state);
485 free_extent_state(state);
490 merge_state(tree, state);
491 next = next_state(state);
496 static struct extent_state *
497 alloc_extent_state_atomic(struct extent_state *prealloc)
500 prealloc = alloc_extent_state(GFP_ATOMIC);
505 static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
507 btrfs_panic(tree_fs_info(tree), err, "Locking error: "
508 "Extent tree was modified by another "
509 "thread while locked.");
513 * clear some bits on a range in the tree. This may require splitting
514 * or inserting elements in the tree, so the gfp mask is used to
515 * indicate which allocations or sleeping are allowed.
517 * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
518 * the given range from the tree regardless of state (ie for truncate).
520 * the range [start, end] is inclusive.
522 * This takes the tree lock, and returns 0 on success and < 0 on error.
524 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
525 unsigned long bits, int wake, int delete,
526 struct extent_state **cached_state,
529 struct extent_state *state;
530 struct extent_state *cached;
531 struct extent_state *prealloc = NULL;
532 struct rb_node *node;
537 btrfs_debug_check_extent_io_range(tree->mapping->host, start, end);
539 if (bits & EXTENT_DELALLOC)
540 bits |= EXTENT_NORESERVE;
543 bits |= ~EXTENT_CTLBITS;
544 bits |= EXTENT_FIRST_DELALLOC;
546 if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
549 if (!prealloc && (mask & __GFP_WAIT)) {
550 prealloc = alloc_extent_state(mask);
555 spin_lock(&tree->lock);
557 cached = *cached_state;
560 *cached_state = NULL;
564 if (cached && cached->tree && cached->start <= start &&
565 cached->end > start) {
567 atomic_dec(&cached->refs);
572 free_extent_state(cached);
575 * this search will find the extents that end after
578 node = tree_search(tree, start);
581 state = rb_entry(node, struct extent_state, rb_node);
583 if (state->start > end)
585 WARN_ON(state->end < start);
586 last_end = state->end;
588 /* the state doesn't have the wanted bits, go ahead */
589 if (!(state->state & bits)) {
590 state = next_state(state);
595 * | ---- desired range ---- |
597 * | ------------- state -------------- |
599 * We need to split the extent we found, and may flip
600 * bits on second half.
602 * If the extent we found extends past our range, we
603 * just split and search again. It'll get split again
604 * the next time though.
606 * If the extent we found is inside our range, we clear
607 * the desired bit on it.
610 if (state->start < start) {
611 prealloc = alloc_extent_state_atomic(prealloc);
613 err = split_state(tree, state, prealloc, start);
615 extent_io_tree_panic(tree, err);
620 if (state->end <= end) {
621 state = clear_state_bit(tree, state, &bits, wake);
627 * | ---- desired range ---- |
629 * We need to split the extent, and clear the bit
632 if (state->start <= end && state->end > end) {
633 prealloc = alloc_extent_state_atomic(prealloc);
635 err = split_state(tree, state, prealloc, end + 1);
637 extent_io_tree_panic(tree, err);
642 clear_state_bit(tree, prealloc, &bits, wake);
648 state = clear_state_bit(tree, state, &bits, wake);
650 if (last_end == (u64)-1)
652 start = last_end + 1;
653 if (start <= end && state && !need_resched())
658 spin_unlock(&tree->lock);
660 free_extent_state(prealloc);
667 spin_unlock(&tree->lock);
668 if (mask & __GFP_WAIT)
673 static void wait_on_state(struct extent_io_tree *tree,
674 struct extent_state *state)
675 __releases(tree->lock)
676 __acquires(tree->lock)
679 prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
680 spin_unlock(&tree->lock);
682 spin_lock(&tree->lock);
683 finish_wait(&state->wq, &wait);
687 * waits for one or more bits to clear on a range in the state tree.
688 * The range [start, end] is inclusive.
689 * The tree lock is taken by this function
691 static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
694 struct extent_state *state;
695 struct rb_node *node;
697 btrfs_debug_check_extent_io_range(tree->mapping->host, start, end);
699 spin_lock(&tree->lock);
703 * this search will find all the extents that end after
706 node = tree_search(tree, start);
710 state = rb_entry(node, struct extent_state, rb_node);
712 if (state->start > end)
715 if (state->state & bits) {
716 start = state->start;
717 atomic_inc(&state->refs);
718 wait_on_state(tree, state);
719 free_extent_state(state);
722 start = state->end + 1;
727 cond_resched_lock(&tree->lock);
730 spin_unlock(&tree->lock);
733 static void set_state_bits(struct extent_io_tree *tree,
734 struct extent_state *state,
737 unsigned long bits_to_set = *bits & ~EXTENT_CTLBITS;
739 set_state_cb(tree, state, bits);
740 if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
741 u64 range = state->end - state->start + 1;
742 tree->dirty_bytes += range;
744 state->state |= bits_to_set;
747 static void cache_state(struct extent_state *state,
748 struct extent_state **cached_ptr)
750 if (cached_ptr && !(*cached_ptr)) {
751 if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
753 atomic_inc(&state->refs);
759 * set some bits on a range in the tree. This may require allocations or
760 * sleeping, so the gfp mask is used to indicate what is allowed.
762 * If any of the exclusive bits are set, this will fail with -EEXIST if some
763 * part of the range already has the desired bits set. The start of the
764 * existing range is returned in failed_start in this case.
766 * [start, end] is inclusive This takes the tree lock.
769 static int __must_check
770 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
771 unsigned long bits, unsigned long exclusive_bits,
772 u64 *failed_start, struct extent_state **cached_state,
775 struct extent_state *state;
776 struct extent_state *prealloc = NULL;
777 struct rb_node *node;
782 btrfs_debug_check_extent_io_range(tree->mapping->host, start, end);
784 bits |= EXTENT_FIRST_DELALLOC;
786 if (!prealloc && (mask & __GFP_WAIT)) {
787 prealloc = alloc_extent_state(mask);
791 spin_lock(&tree->lock);
792 if (cached_state && *cached_state) {
793 state = *cached_state;
794 if (state->start <= start && state->end > start &&
796 node = &state->rb_node;
801 * this search will find all the extents that end after
804 node = tree_search(tree, start);
806 prealloc = alloc_extent_state_atomic(prealloc);
808 err = insert_state(tree, prealloc, start, end, &bits);
810 extent_io_tree_panic(tree, err);
815 state = rb_entry(node, struct extent_state, rb_node);
817 last_start = state->start;
818 last_end = state->end;
821 * | ---- desired range ---- |
824 * Just lock what we found and keep going
826 if (state->start == start && state->end <= end) {
827 if (state->state & exclusive_bits) {
828 *failed_start = state->start;
833 set_state_bits(tree, state, &bits);
834 cache_state(state, cached_state);
835 merge_state(tree, state);
836 if (last_end == (u64)-1)
838 start = last_end + 1;
839 state = next_state(state);
840 if (start < end && state && state->start == start &&
847 * | ---- desired range ---- |
850 * | ------------- state -------------- |
852 * We need to split the extent we found, and may flip bits on
855 * If the extent we found extends past our
856 * range, we just split and search again. It'll get split
857 * again the next time though.
859 * If the extent we found is inside our range, we set the
862 if (state->start < start) {
863 if (state->state & exclusive_bits) {
864 *failed_start = start;
869 prealloc = alloc_extent_state_atomic(prealloc);
871 err = split_state(tree, state, prealloc, start);
873 extent_io_tree_panic(tree, err);
878 if (state->end <= end) {
879 set_state_bits(tree, state, &bits);
880 cache_state(state, cached_state);
881 merge_state(tree, state);
882 if (last_end == (u64)-1)
884 start = last_end + 1;
885 state = next_state(state);
886 if (start < end && state && state->start == start &&
893 * | ---- desired range ---- |
894 * | state | or | state |
896 * There's a hole, we need to insert something in it and
897 * ignore the extent we found.
899 if (state->start > start) {
901 if (end < last_start)
904 this_end = last_start - 1;
906 prealloc = alloc_extent_state_atomic(prealloc);
910 * Avoid to free 'prealloc' if it can be merged with
913 err = insert_state(tree, prealloc, start, this_end,
916 extent_io_tree_panic(tree, err);
918 cache_state(prealloc, cached_state);
920 start = this_end + 1;
924 * | ---- desired range ---- |
926 * We need to split the extent, and set the bit
929 if (state->start <= end && state->end > end) {
930 if (state->state & exclusive_bits) {
931 *failed_start = start;
936 prealloc = alloc_extent_state_atomic(prealloc);
938 err = split_state(tree, state, prealloc, end + 1);
940 extent_io_tree_panic(tree, err);
942 set_state_bits(tree, prealloc, &bits);
943 cache_state(prealloc, cached_state);
944 merge_state(tree, prealloc);
952 spin_unlock(&tree->lock);
954 free_extent_state(prealloc);
961 spin_unlock(&tree->lock);
962 if (mask & __GFP_WAIT)
967 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
968 unsigned long bits, u64 * failed_start,
969 struct extent_state **cached_state, gfp_t mask)
971 return __set_extent_bit(tree, start, end, bits, 0, failed_start,
977 * convert_extent_bit - convert all bits in a given range from one bit to
979 * @tree: the io tree to search
980 * @start: the start offset in bytes
981 * @end: the end offset in bytes (inclusive)
982 * @bits: the bits to set in this range
983 * @clear_bits: the bits to clear in this range
984 * @cached_state: state that we're going to cache
985 * @mask: the allocation mask
987 * This will go through and set bits for the given range. If any states exist
988 * already in this range they are set with the given bit and cleared of the
989 * clear_bits. This is only meant to be used by things that are mergeable, ie
990 * converting from say DELALLOC to DIRTY. This is not meant to be used with
991 * boundary bits like LOCK.
993 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
994 unsigned long bits, unsigned long clear_bits,
995 struct extent_state **cached_state, gfp_t mask)
997 struct extent_state *state;
998 struct extent_state *prealloc = NULL;
999 struct rb_node *node;
1004 btrfs_debug_check_extent_io_range(tree->mapping->host, start, end);
1007 if (!prealloc && (mask & __GFP_WAIT)) {
1008 prealloc = alloc_extent_state(mask);
1013 spin_lock(&tree->lock);
1014 if (cached_state && *cached_state) {
1015 state = *cached_state;
1016 if (state->start <= start && state->end > start &&
1018 node = &state->rb_node;
1024 * this search will find all the extents that end after
1027 node = tree_search(tree, start);
1029 prealloc = alloc_extent_state_atomic(prealloc);
1034 err = insert_state(tree, prealloc, start, end, &bits);
1037 extent_io_tree_panic(tree, err);
1040 state = rb_entry(node, struct extent_state, rb_node);
1042 last_start = state->start;
1043 last_end = state->end;
1046 * | ---- desired range ---- |
1049 * Just lock what we found and keep going
1051 if (state->start == start && state->end <= end) {
1052 set_state_bits(tree, state, &bits);
1053 cache_state(state, cached_state);
1054 state = clear_state_bit(tree, state, &clear_bits, 0);
1055 if (last_end == (u64)-1)
1057 start = last_end + 1;
1058 if (start < end && state && state->start == start &&
1065 * | ---- desired range ---- |
1068 * | ------------- state -------------- |
1070 * We need to split the extent we found, and may flip bits on
1073 * If the extent we found extends past our
1074 * range, we just split and search again. It'll get split
1075 * again the next time though.
1077 * If the extent we found is inside our range, we set the
1078 * desired bit on it.
1080 if (state->start < start) {
1081 prealloc = alloc_extent_state_atomic(prealloc);
1086 err = split_state(tree, state, prealloc, start);
1088 extent_io_tree_panic(tree, err);
1092 if (state->end <= end) {
1093 set_state_bits(tree, state, &bits);
1094 cache_state(state, cached_state);
1095 state = clear_state_bit(tree, state, &clear_bits, 0);
1096 if (last_end == (u64)-1)
1098 start = last_end + 1;
1099 if (start < end && state && state->start == start &&
1106 * | ---- desired range ---- |
1107 * | state | or | state |
1109 * There's a hole, we need to insert something in it and
1110 * ignore the extent we found.
1112 if (state->start > start) {
1114 if (end < last_start)
1117 this_end = last_start - 1;
1119 prealloc = alloc_extent_state_atomic(prealloc);
1126 * Avoid to free 'prealloc' if it can be merged with
1129 err = insert_state(tree, prealloc, start, this_end,
1132 extent_io_tree_panic(tree, err);
1133 cache_state(prealloc, cached_state);
1135 start = this_end + 1;
1139 * | ---- desired range ---- |
1141 * We need to split the extent, and set the bit
1144 if (state->start <= end && state->end > end) {
1145 prealloc = alloc_extent_state_atomic(prealloc);
1151 err = split_state(tree, state, prealloc, end + 1);
1153 extent_io_tree_panic(tree, err);
1155 set_state_bits(tree, prealloc, &bits);
1156 cache_state(prealloc, cached_state);
1157 clear_state_bit(tree, prealloc, &clear_bits, 0);
1165 spin_unlock(&tree->lock);
1167 free_extent_state(prealloc);
1174 spin_unlock(&tree->lock);
1175 if (mask & __GFP_WAIT)
1180 /* wrappers around set/clear extent bit */
1181 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1184 return set_extent_bit(tree, start, end, EXTENT_DIRTY, NULL,
1188 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1189 unsigned long bits, gfp_t mask)
1191 return set_extent_bit(tree, start, end, bits, NULL,
1195 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1196 unsigned long bits, gfp_t mask)
1198 return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
1201 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
1202 struct extent_state **cached_state, gfp_t mask)
1204 return set_extent_bit(tree, start, end,
1205 EXTENT_DELALLOC | EXTENT_UPTODATE,
1206 NULL, cached_state, mask);
1209 int set_extent_defrag(struct extent_io_tree *tree, u64 start, u64 end,
1210 struct extent_state **cached_state, gfp_t mask)
1212 return set_extent_bit(tree, start, end,
1213 EXTENT_DELALLOC | EXTENT_UPTODATE | EXTENT_DEFRAG,
1214 NULL, cached_state, mask);
1217 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
1220 return clear_extent_bit(tree, start, end,
1221 EXTENT_DIRTY | EXTENT_DELALLOC |
1222 EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
1225 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
1228 return set_extent_bit(tree, start, end, EXTENT_NEW, NULL,
1232 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
1233 struct extent_state **cached_state, gfp_t mask)
1235 return set_extent_bit(tree, start, end, EXTENT_UPTODATE, NULL,
1236 cached_state, mask);
1239 int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
1240 struct extent_state **cached_state, gfp_t mask)
1242 return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
1243 cached_state, mask);
1247 * either insert or lock state struct between start and end use mask to tell
1248 * us if waiting is desired.
1250 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
1251 unsigned long bits, struct extent_state **cached_state)
1256 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
1257 EXTENT_LOCKED, &failed_start,
1258 cached_state, GFP_NOFS);
1259 if (err == -EEXIST) {
1260 wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
1261 start = failed_start;
1264 WARN_ON(start > end);
1269 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1271 return lock_extent_bits(tree, start, end, 0, NULL);
1274 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1279 err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
1280 &failed_start, NULL, GFP_NOFS);
1281 if (err == -EEXIST) {
1282 if (failed_start > start)
1283 clear_extent_bit(tree, start, failed_start - 1,
1284 EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS);
1290 int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
1291 struct extent_state **cached, gfp_t mask)
1293 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
1297 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end)
1299 return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
1303 int extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
1305 unsigned long index = start >> PAGE_CACHE_SHIFT;
1306 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1309 while (index <= end_index) {
1310 page = find_get_page(inode->i_mapping, index);
1311 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1312 clear_page_dirty_for_io(page);
1313 page_cache_release(page);
1319 int extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
1321 unsigned long index = start >> PAGE_CACHE_SHIFT;
1322 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1325 while (index <= end_index) {
1326 page = find_get_page(inode->i_mapping, index);
1327 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1328 account_page_redirty(page);
1329 __set_page_dirty_nobuffers(page);
1330 page_cache_release(page);
1337 * helper function to set both pages and extents in the tree writeback
1339 static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
1341 unsigned long index = start >> PAGE_CACHE_SHIFT;
1342 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1345 while (index <= end_index) {
1346 page = find_get_page(tree->mapping, index);
1347 BUG_ON(!page); /* Pages should be in the extent_io_tree */
1348 set_page_writeback(page);
1349 page_cache_release(page);
1355 /* find the first state struct with 'bits' set after 'start', and
1356 * return it. tree->lock must be held. NULL will returned if
1357 * nothing was found after 'start'
1359 static struct extent_state *
1360 find_first_extent_bit_state(struct extent_io_tree *tree,
1361 u64 start, unsigned long bits)
1363 struct rb_node *node;
1364 struct extent_state *state;
1367 * this search will find all the extents that end after
1370 node = tree_search(tree, start);
1375 state = rb_entry(node, struct extent_state, rb_node);
1376 if (state->end >= start && (state->state & bits))
1379 node = rb_next(node);
1388 * find the first offset in the io tree with 'bits' set. zero is
1389 * returned if we find something, and *start_ret and *end_ret are
1390 * set to reflect the state struct that was found.
1392 * If nothing was found, 1 is returned. If found something, return 0.
1394 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
1395 u64 *start_ret, u64 *end_ret, unsigned long bits,
1396 struct extent_state **cached_state)
1398 struct extent_state *state;
1402 spin_lock(&tree->lock);
1403 if (cached_state && *cached_state) {
1404 state = *cached_state;
1405 if (state->end == start - 1 && state->tree) {
1406 n = rb_next(&state->rb_node);
1408 state = rb_entry(n, struct extent_state,
1410 if (state->state & bits)
1414 free_extent_state(*cached_state);
1415 *cached_state = NULL;
1418 free_extent_state(*cached_state);
1419 *cached_state = NULL;
1422 state = find_first_extent_bit_state(tree, start, bits);
1425 cache_state(state, cached_state);
1426 *start_ret = state->start;
1427 *end_ret = state->end;
1431 spin_unlock(&tree->lock);
1436 * find a contiguous range of bytes in the file marked as delalloc, not
1437 * more than 'max_bytes'. start and end are used to return the range,
1439 * 1 is returned if we find something, 0 if nothing was in the tree
1441 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
1442 u64 *start, u64 *end, u64 max_bytes,
1443 struct extent_state **cached_state)
1445 struct rb_node *node;
1446 struct extent_state *state;
1447 u64 cur_start = *start;
1449 u64 total_bytes = 0;
1451 spin_lock(&tree->lock);
1454 * this search will find all the extents that end after
1457 node = tree_search(tree, cur_start);
1465 state = rb_entry(node, struct extent_state, rb_node);
1466 if (found && (state->start != cur_start ||
1467 (state->state & EXTENT_BOUNDARY))) {
1470 if (!(state->state & EXTENT_DELALLOC)) {
1476 *start = state->start;
1477 *cached_state = state;
1478 atomic_inc(&state->refs);
1482 cur_start = state->end + 1;
1483 node = rb_next(node);
1486 total_bytes += state->end - state->start + 1;
1487 if (total_bytes >= max_bytes)
1491 spin_unlock(&tree->lock);
1495 static noinline void __unlock_for_delalloc(struct inode *inode,
1496 struct page *locked_page,
1500 struct page *pages[16];
1501 unsigned long index = start >> PAGE_CACHE_SHIFT;
1502 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1503 unsigned long nr_pages = end_index - index + 1;
1506 if (index == locked_page->index && end_index == index)
1509 while (nr_pages > 0) {
1510 ret = find_get_pages_contig(inode->i_mapping, index,
1511 min_t(unsigned long, nr_pages,
1512 ARRAY_SIZE(pages)), pages);
1513 for (i = 0; i < ret; i++) {
1514 if (pages[i] != locked_page)
1515 unlock_page(pages[i]);
1516 page_cache_release(pages[i]);
1524 static noinline int lock_delalloc_pages(struct inode *inode,
1525 struct page *locked_page,
1529 unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
1530 unsigned long start_index = index;
1531 unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
1532 unsigned long pages_locked = 0;
1533 struct page *pages[16];
1534 unsigned long nrpages;
1538 /* the caller is responsible for locking the start index */
1539 if (index == locked_page->index && index == end_index)
1542 /* skip the page at the start index */
1543 nrpages = end_index - index + 1;
1544 while (nrpages > 0) {
1545 ret = find_get_pages_contig(inode->i_mapping, index,
1546 min_t(unsigned long,
1547 nrpages, ARRAY_SIZE(pages)), pages);
1552 /* now we have an array of pages, lock them all */
1553 for (i = 0; i < ret; i++) {
1555 * the caller is taking responsibility for
1558 if (pages[i] != locked_page) {
1559 lock_page(pages[i]);
1560 if (!PageDirty(pages[i]) ||
1561 pages[i]->mapping != inode->i_mapping) {
1563 unlock_page(pages[i]);
1564 page_cache_release(pages[i]);
1568 page_cache_release(pages[i]);
1577 if (ret && pages_locked) {
1578 __unlock_for_delalloc(inode, locked_page,
1580 ((u64)(start_index + pages_locked - 1)) <<
1587 * find a contiguous range of bytes in the file marked as delalloc, not
1588 * more than 'max_bytes'. start and end are used to return the range,
1590 * 1 is returned if we find something, 0 if nothing was in the tree
1592 static noinline u64 find_lock_delalloc_range(struct inode *inode,
1593 struct extent_io_tree *tree,
1594 struct page *locked_page,
1595 u64 *start, u64 *end,
1601 struct extent_state *cached_state = NULL;
1606 /* step one, find a bunch of delalloc bytes starting at start */
1607 delalloc_start = *start;
1609 found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
1610 max_bytes, &cached_state);
1611 if (!found || delalloc_end <= *start) {
1612 *start = delalloc_start;
1613 *end = delalloc_end;
1614 free_extent_state(cached_state);
1619 * start comes from the offset of locked_page. We have to lock
1620 * pages in order, so we can't process delalloc bytes before
1623 if (delalloc_start < *start)
1624 delalloc_start = *start;
1627 * make sure to limit the number of pages we try to lock down
1630 if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
1631 delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
1633 /* step two, lock all the pages after the page that has start */
1634 ret = lock_delalloc_pages(inode, locked_page,
1635 delalloc_start, delalloc_end);
1636 if (ret == -EAGAIN) {
1637 /* some of the pages are gone, lets avoid looping by
1638 * shortening the size of the delalloc range we're searching
1640 free_extent_state(cached_state);
1642 unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
1643 max_bytes = PAGE_CACHE_SIZE - offset;
1651 BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
1653 /* step three, lock the state bits for the whole range */
1654 lock_extent_bits(tree, delalloc_start, delalloc_end, 0, &cached_state);
1656 /* then test to make sure it is all still delalloc */
1657 ret = test_range_bit(tree, delalloc_start, delalloc_end,
1658 EXTENT_DELALLOC, 1, cached_state);
1660 unlock_extent_cached(tree, delalloc_start, delalloc_end,
1661 &cached_state, GFP_NOFS);
1662 __unlock_for_delalloc(inode, locked_page,
1663 delalloc_start, delalloc_end);
1667 free_extent_state(cached_state);
1668 *start = delalloc_start;
1669 *end = delalloc_end;
1674 int extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
1675 struct page *locked_page,
1676 unsigned long clear_bits,
1677 unsigned long page_ops)
1679 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
1681 struct page *pages[16];
1682 unsigned long index = start >> PAGE_CACHE_SHIFT;
1683 unsigned long end_index = end >> PAGE_CACHE_SHIFT;
1684 unsigned long nr_pages = end_index - index + 1;
1687 clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
1691 while (nr_pages > 0) {
1692 ret = find_get_pages_contig(inode->i_mapping, index,
1693 min_t(unsigned long,
1694 nr_pages, ARRAY_SIZE(pages)), pages);
1695 for (i = 0; i < ret; i++) {
1697 if (page_ops & PAGE_SET_PRIVATE2)
1698 SetPagePrivate2(pages[i]);
1700 if (pages[i] == locked_page) {
1701 page_cache_release(pages[i]);
1704 if (page_ops & PAGE_CLEAR_DIRTY)
1705 clear_page_dirty_for_io(pages[i]);
1706 if (page_ops & PAGE_SET_WRITEBACK)
1707 set_page_writeback(pages[i]);
1708 if (page_ops & PAGE_END_WRITEBACK)
1709 end_page_writeback(pages[i]);
1710 if (page_ops & PAGE_UNLOCK)
1711 unlock_page(pages[i]);
1712 page_cache_release(pages[i]);
1722 * count the number of bytes in the tree that have a given bit(s)
1723 * set. This can be fairly slow, except for EXTENT_DIRTY which is
1724 * cached. The total number found is returned.
1726 u64 count_range_bits(struct extent_io_tree *tree,
1727 u64 *start, u64 search_end, u64 max_bytes,
1728 unsigned long bits, int contig)
1730 struct rb_node *node;
1731 struct extent_state *state;
1732 u64 cur_start = *start;
1733 u64 total_bytes = 0;
1737 if (search_end <= cur_start) {
1742 spin_lock(&tree->lock);
1743 if (cur_start == 0 && bits == EXTENT_DIRTY) {
1744 total_bytes = tree->dirty_bytes;
1748 * this search will find all the extents that end after
1751 node = tree_search(tree, cur_start);
1756 state = rb_entry(node, struct extent_state, rb_node);
1757 if (state->start > search_end)
1759 if (contig && found && state->start > last + 1)
1761 if (state->end >= cur_start && (state->state & bits) == bits) {
1762 total_bytes += min(search_end, state->end) + 1 -
1763 max(cur_start, state->start);
1764 if (total_bytes >= max_bytes)
1767 *start = max(cur_start, state->start);
1771 } else if (contig && found) {
1774 node = rb_next(node);
1779 spin_unlock(&tree->lock);
1784 * set the private field for a given byte offset in the tree. If there isn't
1785 * an extent_state there already, this does nothing.
1787 static int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
1789 struct rb_node *node;
1790 struct extent_state *state;
1793 spin_lock(&tree->lock);
1795 * this search will find all the extents that end after
1798 node = tree_search(tree, start);
1803 state = rb_entry(node, struct extent_state, rb_node);
1804 if (state->start != start) {
1808 state->private = private;
1810 spin_unlock(&tree->lock);
1814 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
1816 struct rb_node *node;
1817 struct extent_state *state;
1820 spin_lock(&tree->lock);
1822 * this search will find all the extents that end after
1825 node = tree_search(tree, start);
1830 state = rb_entry(node, struct extent_state, rb_node);
1831 if (state->start != start) {
1835 *private = state->private;
1837 spin_unlock(&tree->lock);
1842 * searches a range in the state tree for a given mask.
1843 * If 'filled' == 1, this returns 1 only if every extent in the tree
1844 * has the bits set. Otherwise, 1 is returned if any bit in the
1845 * range is found set.
1847 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
1848 unsigned long bits, int filled, struct extent_state *cached)
1850 struct extent_state *state = NULL;
1851 struct rb_node *node;
1854 spin_lock(&tree->lock);
1855 if (cached && cached->tree && cached->start <= start &&
1856 cached->end > start)
1857 node = &cached->rb_node;
1859 node = tree_search(tree, start);
1860 while (node && start <= end) {
1861 state = rb_entry(node, struct extent_state, rb_node);
1863 if (filled && state->start > start) {
1868 if (state->start > end)
1871 if (state->state & bits) {
1875 } else if (filled) {
1880 if (state->end == (u64)-1)
1883 start = state->end + 1;
1886 node = rb_next(node);
1893 spin_unlock(&tree->lock);
1898 * helper function to set a given page up to date if all the
1899 * extents in the tree for that page are up to date
1901 static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
1903 u64 start = page_offset(page);
1904 u64 end = start + PAGE_CACHE_SIZE - 1;
1905 if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
1906 SetPageUptodate(page);
1910 * When IO fails, either with EIO or csum verification fails, we
1911 * try other mirrors that might have a good copy of the data. This
1912 * io_failure_record is used to record state as we go through all the
1913 * mirrors. If another mirror has good data, the page is set up to date
1914 * and things continue. If a good mirror can't be found, the original
1915 * bio end_io callback is called to indicate things have failed.
1917 struct io_failure_record {
1922 unsigned long bio_flags;
1928 static int free_io_failure(struct inode *inode, struct io_failure_record *rec,
1933 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1935 set_state_private(failure_tree, rec->start, 0);
1936 ret = clear_extent_bits(failure_tree, rec->start,
1937 rec->start + rec->len - 1,
1938 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
1942 ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start,
1943 rec->start + rec->len - 1,
1944 EXTENT_DAMAGED, GFP_NOFS);
1952 static void repair_io_failure_callback(struct bio *bio, int err)
1954 complete(bio->bi_private);
1958 * this bypasses the standard btrfs submit functions deliberately, as
1959 * the standard behavior is to write all copies in a raid setup. here we only
1960 * want to write the one bad copy. so we do the mapping for ourselves and issue
1961 * submit_bio directly.
1962 * to avoid any synchronization issues, wait for the data after writing, which
1963 * actually prevents the read that triggered the error from finishing.
1964 * currently, there can be no more than two copies of every data bit. thus,
1965 * exactly one rewrite is required.
1967 int repair_io_failure(struct btrfs_fs_info *fs_info, u64 start,
1968 u64 length, u64 logical, struct page *page,
1972 struct btrfs_device *dev;
1973 DECLARE_COMPLETION_ONSTACK(compl);
1976 struct btrfs_bio *bbio = NULL;
1977 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
1980 BUG_ON(!mirror_num);
1982 /* we can't repair anything in raid56 yet */
1983 if (btrfs_is_parity_mirror(map_tree, logical, length, mirror_num))
1986 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1989 bio->bi_private = &compl;
1990 bio->bi_end_io = repair_io_failure_callback;
1992 map_length = length;
1994 ret = btrfs_map_block(fs_info, WRITE, logical,
1995 &map_length, &bbio, mirror_num);
2000 BUG_ON(mirror_num != bbio->mirror_num);
2001 sector = bbio->stripes[mirror_num-1].physical >> 9;
2002 bio->bi_sector = sector;
2003 dev = bbio->stripes[mirror_num-1].dev;
2005 if (!dev || !dev->bdev || !dev->writeable) {
2009 bio->bi_bdev = dev->bdev;
2010 bio_add_page(bio, page, length, start - page_offset(page));
2011 btrfsic_submit_bio(WRITE_SYNC, bio);
2012 wait_for_completion(&compl);
2014 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
2015 /* try to remap that extent elsewhere? */
2017 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
2021 printk_ratelimited_in_rcu(KERN_INFO "btrfs read error corrected: ino %lu off %llu "
2022 "(dev %s sector %llu)\n", page->mapping->host->i_ino,
2023 start, rcu_str_deref(dev->name), sector);
2029 int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb,
2032 u64 start = eb->start;
2033 unsigned long i, num_pages = num_extent_pages(eb->start, eb->len);
2036 for (i = 0; i < num_pages; i++) {
2037 struct page *p = extent_buffer_page(eb, i);
2038 ret = repair_io_failure(root->fs_info, start, PAGE_CACHE_SIZE,
2039 start, p, mirror_num);
2042 start += PAGE_CACHE_SIZE;
2049 * each time an IO finishes, we do a fast check in the IO failure tree
2050 * to see if we need to process or clean up an io_failure_record
2052 static int clean_io_failure(u64 start, struct page *page)
2055 u64 private_failure;
2056 struct io_failure_record *failrec;
2057 struct btrfs_fs_info *fs_info;
2058 struct extent_state *state;
2062 struct inode *inode = page->mapping->host;
2065 ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
2066 (u64)-1, 1, EXTENT_DIRTY, 0);
2070 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree, start,
2075 failrec = (struct io_failure_record *)(unsigned long) private_failure;
2076 BUG_ON(!failrec->this_mirror);
2078 if (failrec->in_validation) {
2079 /* there was no real error, just free the record */
2080 pr_debug("clean_io_failure: freeing dummy error at %llu\n",
2086 spin_lock(&BTRFS_I(inode)->io_tree.lock);
2087 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
2090 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
2092 if (state && state->start <= failrec->start &&
2093 state->end >= failrec->start + failrec->len - 1) {
2094 fs_info = BTRFS_I(inode)->root->fs_info;
2095 num_copies = btrfs_num_copies(fs_info, failrec->logical,
2097 if (num_copies > 1) {
2098 ret = repair_io_failure(fs_info, start, failrec->len,
2099 failrec->logical, page,
2100 failrec->failed_mirror);
2108 ret = free_io_failure(inode, failrec, did_repair);
2114 * this is a generic handler for readpage errors (default
2115 * readpage_io_failed_hook). if other copies exist, read those and write back
2116 * good data to the failed position. does not investigate in remapping the
2117 * failed extent elsewhere, hoping the device will be smart enough to do this as
2121 static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
2122 struct page *page, u64 start, u64 end,
2125 struct io_failure_record *failrec = NULL;
2127 struct extent_map *em;
2128 struct inode *inode = page->mapping->host;
2129 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
2130 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2131 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2133 struct btrfs_io_bio *btrfs_failed_bio;
2134 struct btrfs_io_bio *btrfs_bio;
2140 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
2142 ret = get_state_private(failure_tree, start, &private);
2144 failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
2147 failrec->start = start;
2148 failrec->len = end - start + 1;
2149 failrec->this_mirror = 0;
2150 failrec->bio_flags = 0;
2151 failrec->in_validation = 0;
2153 read_lock(&em_tree->lock);
2154 em = lookup_extent_mapping(em_tree, start, failrec->len);
2156 read_unlock(&em_tree->lock);
2161 if (em->start > start || em->start + em->len < start) {
2162 free_extent_map(em);
2165 read_unlock(&em_tree->lock);
2171 logical = start - em->start;
2172 logical = em->block_start + logical;
2173 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2174 logical = em->block_start;
2175 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
2176 extent_set_compress_type(&failrec->bio_flags,
2179 pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
2180 "len=%llu\n", logical, start, failrec->len);
2181 failrec->logical = logical;
2182 free_extent_map(em);
2184 /* set the bits in the private failure tree */
2185 ret = set_extent_bits(failure_tree, start, end,
2186 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
2188 ret = set_state_private(failure_tree, start,
2189 (u64)(unsigned long)failrec);
2190 /* set the bits in the inode's tree */
2192 ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED,
2199 failrec = (struct io_failure_record *)(unsigned long)private;
2200 pr_debug("bio_readpage_error: (found) logical=%llu, "
2201 "start=%llu, len=%llu, validation=%d\n",
2202 failrec->logical, failrec->start, failrec->len,
2203 failrec->in_validation);
2205 * when data can be on disk more than twice, add to failrec here
2206 * (e.g. with a list for failed_mirror) to make
2207 * clean_io_failure() clean all those errors at once.
2210 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
2211 failrec->logical, failrec->len);
2212 if (num_copies == 1) {
2214 * we only have a single copy of the data, so don't bother with
2215 * all the retry and error correction code that follows. no
2216 * matter what the error is, it is very likely to persist.
2218 pr_debug("bio_readpage_error: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
2219 num_copies, failrec->this_mirror, failed_mirror);
2220 free_io_failure(inode, failrec, 0);
2225 * there are two premises:
2226 * a) deliver good data to the caller
2227 * b) correct the bad sectors on disk
2229 if (failed_bio->bi_vcnt > 1) {
2231 * to fulfill b), we need to know the exact failing sectors, as
2232 * we don't want to rewrite any more than the failed ones. thus,
2233 * we need separate read requests for the failed bio
2235 * if the following BUG_ON triggers, our validation request got
2236 * merged. we need separate requests for our algorithm to work.
2238 BUG_ON(failrec->in_validation);
2239 failrec->in_validation = 1;
2240 failrec->this_mirror = failed_mirror;
2241 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
2244 * we're ready to fulfill a) and b) alongside. get a good copy
2245 * of the failed sector and if we succeed, we have setup
2246 * everything for repair_io_failure to do the rest for us.
2248 if (failrec->in_validation) {
2249 BUG_ON(failrec->this_mirror != failed_mirror);
2250 failrec->in_validation = 0;
2251 failrec->this_mirror = 0;
2253 failrec->failed_mirror = failed_mirror;
2254 failrec->this_mirror++;
2255 if (failrec->this_mirror == failed_mirror)
2256 failrec->this_mirror++;
2257 read_mode = READ_SYNC;
2260 if (failrec->this_mirror > num_copies) {
2261 pr_debug("bio_readpage_error: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
2262 num_copies, failrec->this_mirror, failed_mirror);
2263 free_io_failure(inode, failrec, 0);
2267 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
2269 free_io_failure(inode, failrec, 0);
2272 bio->bi_end_io = failed_bio->bi_end_io;
2273 bio->bi_sector = failrec->logical >> 9;
2274 bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
2277 btrfs_failed_bio = btrfs_io_bio(failed_bio);
2278 if (btrfs_failed_bio->csum) {
2279 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2280 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
2282 btrfs_bio = btrfs_io_bio(bio);
2283 btrfs_bio->csum = btrfs_bio->csum_inline;
2284 phy_offset >>= inode->i_sb->s_blocksize_bits;
2285 phy_offset *= csum_size;
2286 memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + phy_offset,
2290 bio_add_page(bio, page, failrec->len, start - page_offset(page));
2292 pr_debug("bio_readpage_error: submitting new read[%#x] to "
2293 "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode,
2294 failrec->this_mirror, num_copies, failrec->in_validation);
2296 ret = tree->ops->submit_bio_hook(inode, read_mode, bio,
2297 failrec->this_mirror,
2298 failrec->bio_flags, 0);
2302 /* lots and lots of room for performance fixes in the end_bio funcs */
2304 int end_extent_writepage(struct page *page, int err, u64 start, u64 end)
2306 int uptodate = (err == 0);
2307 struct extent_io_tree *tree;
2310 tree = &BTRFS_I(page->mapping->host)->io_tree;
2312 if (tree->ops && tree->ops->writepage_end_io_hook) {
2313 ret = tree->ops->writepage_end_io_hook(page, start,
2314 end, NULL, uptodate);
2320 ClearPageUptodate(page);
2327 * after a writepage IO is done, we need to:
2328 * clear the uptodate bits on error
2329 * clear the writeback bits in the extent tree for this IO
2330 * end_page_writeback if the page has no more pending IO
2332 * Scheduling is not allowed, so the extent state tree is expected
2333 * to have one and only one object corresponding to this IO.
2335 static void end_bio_extent_writepage(struct bio *bio, int err)
2337 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2338 struct extent_io_tree *tree;
2343 struct page *page = bvec->bv_page;
2344 tree = &BTRFS_I(page->mapping->host)->io_tree;
2346 /* We always issue full-page reads, but if some block
2347 * in a page fails to read, blk_update_request() will
2348 * advance bv_offset and adjust bv_len to compensate.
2349 * Print a warning for nonzero offsets, and an error
2350 * if they don't add up to a full page. */
2351 if (bvec->bv_offset || bvec->bv_len != PAGE_CACHE_SIZE)
2352 printk("%s page write in btrfs with offset %u and length %u\n",
2353 bvec->bv_offset + bvec->bv_len != PAGE_CACHE_SIZE
2354 ? KERN_ERR "partial" : KERN_INFO "incomplete",
2355 bvec->bv_offset, bvec->bv_len);
2357 start = page_offset(page);
2358 end = start + bvec->bv_offset + bvec->bv_len - 1;
2360 if (--bvec >= bio->bi_io_vec)
2361 prefetchw(&bvec->bv_page->flags);
2363 if (end_extent_writepage(page, err, start, end))
2366 end_page_writeback(page);
2367 } while (bvec >= bio->bi_io_vec);
2373 endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
2376 struct extent_state *cached = NULL;
2377 u64 end = start + len - 1;
2379 if (uptodate && tree->track_uptodate)
2380 set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
2381 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
2385 * after a readpage IO is done, we need to:
2386 * clear the uptodate bits on error
2387 * set the uptodate bits if things worked
2388 * set the page up to date if all extents in the tree are uptodate
2389 * clear the lock bit in the extent tree
2390 * unlock the page if there are no other extents locked for it
2392 * Scheduling is not allowed, so the extent state tree is expected
2393 * to have one and only one object corresponding to this IO.
2395 static void end_bio_extent_readpage(struct bio *bio, int err)
2397 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
2398 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
2399 struct bio_vec *bvec = bio->bi_io_vec;
2400 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
2401 struct extent_io_tree *tree;
2406 u64 extent_start = 0;
2415 struct page *page = bvec->bv_page;
2416 struct inode *inode = page->mapping->host;
2418 pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
2419 "mirror=%lu\n", (u64)bio->bi_sector, err,
2420 io_bio->mirror_num);
2421 tree = &BTRFS_I(inode)->io_tree;
2423 /* We always issue full-page reads, but if some block
2424 * in a page fails to read, blk_update_request() will
2425 * advance bv_offset and adjust bv_len to compensate.
2426 * Print a warning for nonzero offsets, and an error
2427 * if they don't add up to a full page. */
2428 if (bvec->bv_offset || bvec->bv_len != PAGE_CACHE_SIZE)
2429 printk("%s page read in btrfs with offset %u and length %u\n",
2430 bvec->bv_offset + bvec->bv_len != PAGE_CACHE_SIZE
2431 ? KERN_ERR "partial" : KERN_INFO "incomplete",
2432 bvec->bv_offset, bvec->bv_len);
2434 start = page_offset(page);
2435 end = start + bvec->bv_offset + bvec->bv_len - 1;
2438 if (++bvec <= bvec_end)
2439 prefetchw(&bvec->bv_page->flags);
2441 mirror = io_bio->mirror_num;
2442 if (likely(uptodate && tree->ops &&
2443 tree->ops->readpage_end_io_hook)) {
2444 ret = tree->ops->readpage_end_io_hook(io_bio, offset,
2450 clean_io_failure(start, page);
2453 if (likely(uptodate))
2456 if (tree->ops && tree->ops->readpage_io_failed_hook) {
2457 ret = tree->ops->readpage_io_failed_hook(page, mirror);
2459 test_bit(BIO_UPTODATE, &bio->bi_flags))
2463 * The generic bio_readpage_error handles errors the
2464 * following way: If possible, new read requests are
2465 * created and submitted and will end up in
2466 * end_bio_extent_readpage as well (if we're lucky, not
2467 * in the !uptodate case). In that case it returns 0 and
2468 * we just go on with the next page in our bio. If it
2469 * can't handle the error it will return -EIO and we
2470 * remain responsible for that page.
2472 ret = bio_readpage_error(bio, offset, page, start, end,
2476 test_bit(BIO_UPTODATE, &bio->bi_flags);
2483 if (likely(uptodate)) {
2484 loff_t i_size = i_size_read(inode);
2485 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
2488 /* Zero out the end if this page straddles i_size */
2489 offset = i_size & (PAGE_CACHE_SIZE-1);
2490 if (page->index == end_index && offset)
2491 zero_user_segment(page, offset, PAGE_CACHE_SIZE);
2492 SetPageUptodate(page);
2494 ClearPageUptodate(page);
2500 if (unlikely(!uptodate)) {
2502 endio_readpage_release_extent(tree,
2508 endio_readpage_release_extent(tree, start,
2509 end - start + 1, 0);
2510 } else if (!extent_len) {
2511 extent_start = start;
2512 extent_len = end + 1 - start;
2513 } else if (extent_start + extent_len == start) {
2514 extent_len += end + 1 - start;
2516 endio_readpage_release_extent(tree, extent_start,
2517 extent_len, uptodate);
2518 extent_start = start;
2519 extent_len = end + 1 - start;
2521 } while (bvec <= bvec_end);
2524 endio_readpage_release_extent(tree, extent_start, extent_len,
2527 io_bio->end_io(io_bio, err);
2532 * this allocates from the btrfs_bioset. We're returning a bio right now
2533 * but you can call btrfs_io_bio for the appropriate container_of magic
2536 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
2539 struct btrfs_io_bio *btrfs_bio;
2542 bio = bio_alloc_bioset(gfp_flags, nr_vecs, btrfs_bioset);
2544 if (bio == NULL && (current->flags & PF_MEMALLOC)) {
2545 while (!bio && (nr_vecs /= 2)) {
2546 bio = bio_alloc_bioset(gfp_flags,
2547 nr_vecs, btrfs_bioset);
2553 bio->bi_bdev = bdev;
2554 bio->bi_sector = first_sector;
2555 btrfs_bio = btrfs_io_bio(bio);
2556 btrfs_bio->csum = NULL;
2557 btrfs_bio->csum_allocated = NULL;
2558 btrfs_bio->end_io = NULL;
2563 struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
2565 return bio_clone_bioset(bio, gfp_mask, btrfs_bioset);
2569 /* this also allocates from the btrfs_bioset */
2570 struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
2572 struct btrfs_io_bio *btrfs_bio;
2575 bio = bio_alloc_bioset(gfp_mask, nr_iovecs, btrfs_bioset);
2577 btrfs_bio = btrfs_io_bio(bio);
2578 btrfs_bio->csum = NULL;
2579 btrfs_bio->csum_allocated = NULL;
2580 btrfs_bio->end_io = NULL;
2586 static int __must_check submit_one_bio(int rw, struct bio *bio,
2587 int mirror_num, unsigned long bio_flags)
2590 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
2591 struct page *page = bvec->bv_page;
2592 struct extent_io_tree *tree = bio->bi_private;
2595 start = page_offset(page) + bvec->bv_offset;
2597 bio->bi_private = NULL;
2601 if (tree->ops && tree->ops->submit_bio_hook)
2602 ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
2603 mirror_num, bio_flags, start);
2605 btrfsic_submit_bio(rw, bio);
2607 if (bio_flagged(bio, BIO_EOPNOTSUPP))
2613 static int merge_bio(int rw, struct extent_io_tree *tree, struct page *page,
2614 unsigned long offset, size_t size, struct bio *bio,
2615 unsigned long bio_flags)
2618 if (tree->ops && tree->ops->merge_bio_hook)
2619 ret = tree->ops->merge_bio_hook(rw, page, offset, size, bio,
2626 static int submit_extent_page(int rw, struct extent_io_tree *tree,
2627 struct page *page, sector_t sector,
2628 size_t size, unsigned long offset,
2629 struct block_device *bdev,
2630 struct bio **bio_ret,
2631 unsigned long max_pages,
2632 bio_end_io_t end_io_func,
2634 unsigned long prev_bio_flags,
2635 unsigned long bio_flags)
2641 int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
2642 int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
2643 size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
2645 if (bio_ret && *bio_ret) {
2648 contig = bio->bi_sector == sector;
2650 contig = bio_end_sector(bio) == sector;
2652 if (prev_bio_flags != bio_flags || !contig ||
2653 merge_bio(rw, tree, page, offset, page_size, bio, bio_flags) ||
2654 bio_add_page(bio, page, page_size, offset) < page_size) {
2655 ret = submit_one_bio(rw, bio, mirror_num,
2664 if (this_compressed)
2667 nr = bio_get_nr_vecs(bdev);
2669 bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
2673 bio_add_page(bio, page, page_size, offset);
2674 bio->bi_end_io = end_io_func;
2675 bio->bi_private = tree;
2680 ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
2685 static void attach_extent_buffer_page(struct extent_buffer *eb,
2688 if (!PagePrivate(page)) {
2689 SetPagePrivate(page);
2690 page_cache_get(page);
2691 set_page_private(page, (unsigned long)eb);
2693 WARN_ON(page->private != (unsigned long)eb);
2697 void set_page_extent_mapped(struct page *page)
2699 if (!PagePrivate(page)) {
2700 SetPagePrivate(page);
2701 page_cache_get(page);
2702 set_page_private(page, EXTENT_PAGE_PRIVATE);
2706 static struct extent_map *
2707 __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
2708 u64 start, u64 len, get_extent_t *get_extent,
2709 struct extent_map **em_cached)
2711 struct extent_map *em;
2713 if (em_cached && *em_cached) {
2715 if (em->in_tree && start >= em->start &&
2716 start < extent_map_end(em)) {
2717 atomic_inc(&em->refs);
2721 free_extent_map(em);
2725 em = get_extent(inode, page, pg_offset, start, len, 0);
2726 if (em_cached && !IS_ERR_OR_NULL(em)) {
2728 atomic_inc(&em->refs);
2734 * basic readpage implementation. Locked extent state structs are inserted
2735 * into the tree that are removed when the IO is done (by the end_io
2737 * XXX JDM: This needs looking at to ensure proper page locking
2739 static int __do_readpage(struct extent_io_tree *tree,
2741 get_extent_t *get_extent,
2742 struct extent_map **em_cached,
2743 struct bio **bio, int mirror_num,
2744 unsigned long *bio_flags, int rw)
2746 struct inode *inode = page->mapping->host;
2747 u64 start = page_offset(page);
2748 u64 page_end = start + PAGE_CACHE_SIZE - 1;
2752 u64 last_byte = i_size_read(inode);
2756 struct extent_map *em;
2757 struct block_device *bdev;
2760 int parent_locked = *bio_flags & EXTENT_BIO_PARENT_LOCKED;
2761 size_t pg_offset = 0;
2763 size_t disk_io_size;
2764 size_t blocksize = inode->i_sb->s_blocksize;
2765 unsigned long this_bio_flag = *bio_flags & EXTENT_BIO_PARENT_LOCKED;
2767 set_page_extent_mapped(page);
2770 if (!PageUptodate(page)) {
2771 if (cleancache_get_page(page) == 0) {
2772 BUG_ON(blocksize != PAGE_SIZE);
2773 unlock_extent(tree, start, end);
2778 if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
2780 size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
2783 iosize = PAGE_CACHE_SIZE - zero_offset;
2784 userpage = kmap_atomic(page);
2785 memset(userpage + zero_offset, 0, iosize);
2786 flush_dcache_page(page);
2787 kunmap_atomic(userpage);
2790 while (cur <= end) {
2791 unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
2793 if (cur >= last_byte) {
2795 struct extent_state *cached = NULL;
2797 iosize = PAGE_CACHE_SIZE - pg_offset;
2798 userpage = kmap_atomic(page);
2799 memset(userpage + pg_offset, 0, iosize);
2800 flush_dcache_page(page);
2801 kunmap_atomic(userpage);
2802 set_extent_uptodate(tree, cur, cur + iosize - 1,
2805 unlock_extent_cached(tree, cur,
2810 em = __get_extent_map(inode, page, pg_offset, cur,
2811 end - cur + 1, get_extent, em_cached);
2812 if (IS_ERR_OR_NULL(em)) {
2815 unlock_extent(tree, cur, end);
2818 extent_offset = cur - em->start;
2819 BUG_ON(extent_map_end(em) <= cur);
2822 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
2823 this_bio_flag |= EXTENT_BIO_COMPRESSED;
2824 extent_set_compress_type(&this_bio_flag,
2828 iosize = min(extent_map_end(em) - cur, end - cur + 1);
2829 cur_end = min(extent_map_end(em) - 1, end);
2830 iosize = ALIGN(iosize, blocksize);
2831 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
2832 disk_io_size = em->block_len;
2833 sector = em->block_start >> 9;
2835 sector = (em->block_start + extent_offset) >> 9;
2836 disk_io_size = iosize;
2839 block_start = em->block_start;
2840 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2841 block_start = EXTENT_MAP_HOLE;
2842 free_extent_map(em);
2845 /* we've found a hole, just zero and go on */
2846 if (block_start == EXTENT_MAP_HOLE) {
2848 struct extent_state *cached = NULL;
2850 userpage = kmap_atomic(page);
2851 memset(userpage + pg_offset, 0, iosize);
2852 flush_dcache_page(page);
2853 kunmap_atomic(userpage);
2855 set_extent_uptodate(tree, cur, cur + iosize - 1,
2857 unlock_extent_cached(tree, cur, cur + iosize - 1,
2860 pg_offset += iosize;
2863 /* the get_extent function already copied into the page */
2864 if (test_range_bit(tree, cur, cur_end,
2865 EXTENT_UPTODATE, 1, NULL)) {
2866 check_page_uptodate(tree, page);
2868 unlock_extent(tree, cur, cur + iosize - 1);
2870 pg_offset += iosize;
2873 /* we have an inline extent but it didn't get marked up
2874 * to date. Error out
2876 if (block_start == EXTENT_MAP_INLINE) {
2879 unlock_extent(tree, cur, cur + iosize - 1);
2881 pg_offset += iosize;
2886 ret = submit_extent_page(rw, tree, page,
2887 sector, disk_io_size, pg_offset,
2889 end_bio_extent_readpage, mirror_num,
2894 *bio_flags = this_bio_flag;
2898 unlock_extent(tree, cur, cur + iosize - 1);
2901 pg_offset += iosize;
2905 if (!PageError(page))
2906 SetPageUptodate(page);
2912 static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
2913 struct page *pages[], int nr_pages,
2915 get_extent_t *get_extent,
2916 struct extent_map **em_cached,
2917 struct bio **bio, int mirror_num,
2918 unsigned long *bio_flags, int rw)
2920 struct inode *inode;
2921 struct btrfs_ordered_extent *ordered;
2924 inode = pages[0]->mapping->host;
2926 lock_extent(tree, start, end);
2927 ordered = btrfs_lookup_ordered_range(inode, start,
2931 unlock_extent(tree, start, end);
2932 btrfs_start_ordered_extent(inode, ordered, 1);
2933 btrfs_put_ordered_extent(ordered);
2936 for (index = 0; index < nr_pages; index++) {
2937 __do_readpage(tree, pages[index], get_extent, em_cached, bio,
2938 mirror_num, bio_flags, rw);
2939 page_cache_release(pages[index]);
2943 static void __extent_readpages(struct extent_io_tree *tree,
2944 struct page *pages[],
2945 int nr_pages, get_extent_t *get_extent,
2946 struct extent_map **em_cached,
2947 struct bio **bio, int mirror_num,
2948 unsigned long *bio_flags, int rw)
2954 int first_index = 0;
2956 for (index = 0; index < nr_pages; index++) {
2957 page_start = page_offset(pages[index]);
2960 end = start + PAGE_CACHE_SIZE - 1;
2961 first_index = index;
2962 } else if (end + 1 == page_start) {
2963 end += PAGE_CACHE_SIZE;
2965 __do_contiguous_readpages(tree, &pages[first_index],
2966 index - first_index, start,
2967 end, get_extent, em_cached,
2968 bio, mirror_num, bio_flags,
2971 end = start + PAGE_CACHE_SIZE - 1;
2972 first_index = index;
2977 __do_contiguous_readpages(tree, &pages[first_index],
2978 index - first_index, start,
2979 end, get_extent, em_cached, bio,
2980 mirror_num, bio_flags, rw);
2983 static int __extent_read_full_page(struct extent_io_tree *tree,
2985 get_extent_t *get_extent,
2986 struct bio **bio, int mirror_num,
2987 unsigned long *bio_flags, int rw)
2989 struct inode *inode = page->mapping->host;
2990 struct btrfs_ordered_extent *ordered;
2991 u64 start = page_offset(page);
2992 u64 end = start + PAGE_CACHE_SIZE - 1;
2996 lock_extent(tree, start, end);
2997 ordered = btrfs_lookup_ordered_extent(inode, start);
3000 unlock_extent(tree, start, end);
3001 btrfs_start_ordered_extent(inode, ordered, 1);
3002 btrfs_put_ordered_extent(ordered);
3005 ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
3010 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
3011 get_extent_t *get_extent, int mirror_num)
3013 struct bio *bio = NULL;
3014 unsigned long bio_flags = 0;
3017 ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
3020 ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
3024 int extent_read_full_page_nolock(struct extent_io_tree *tree, struct page *page,
3025 get_extent_t *get_extent, int mirror_num)
3027 struct bio *bio = NULL;
3028 unsigned long bio_flags = EXTENT_BIO_PARENT_LOCKED;
3031 ret = __do_readpage(tree, page, get_extent, NULL, &bio, mirror_num,
3034 ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
3038 static noinline void update_nr_written(struct page *page,
3039 struct writeback_control *wbc,
3040 unsigned long nr_written)
3042 wbc->nr_to_write -= nr_written;
3043 if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
3044 wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
3045 page->mapping->writeback_index = page->index + nr_written;
3049 * the writepage semantics are similar to regular writepage. extent
3050 * records are inserted to lock ranges in the tree, and as dirty areas
3051 * are found, they are marked writeback. Then the lock bits are removed
3052 * and the end_io handler clears the writeback ranges
3054 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
3057 struct inode *inode = page->mapping->host;
3058 struct extent_page_data *epd = data;
3059 struct extent_io_tree *tree = epd->tree;
3060 u64 start = page_offset(page);
3062 u64 page_end = start + PAGE_CACHE_SIZE - 1;
3066 u64 last_byte = i_size_read(inode);
3070 struct extent_state *cached_state = NULL;
3071 struct extent_map *em;
3072 struct block_device *bdev;
3075 size_t pg_offset = 0;
3077 loff_t i_size = i_size_read(inode);
3078 unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
3084 unsigned long nr_written = 0;
3085 bool fill_delalloc = true;
3087 if (wbc->sync_mode == WB_SYNC_ALL)
3088 write_flags = WRITE_SYNC;
3090 write_flags = WRITE;
3092 trace___extent_writepage(page, inode, wbc);
3094 WARN_ON(!PageLocked(page));
3096 ClearPageError(page);
3098 pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
3099 if (page->index > end_index ||
3100 (page->index == end_index && !pg_offset)) {
3101 page->mapping->a_ops->invalidatepage(page, 0, PAGE_CACHE_SIZE);
3106 if (page->index == end_index) {
3109 userpage = kmap_atomic(page);
3110 memset(userpage + pg_offset, 0,
3111 PAGE_CACHE_SIZE - pg_offset);
3112 kunmap_atomic(userpage);
3113 flush_dcache_page(page);
3117 set_page_extent_mapped(page);
3119 if (!tree->ops || !tree->ops->fill_delalloc)
3120 fill_delalloc = false;
3122 delalloc_start = start;
3125 if (!epd->extent_locked && fill_delalloc) {
3126 u64 delalloc_to_write = 0;
3128 * make sure the wbc mapping index is at least updated
3131 update_nr_written(page, wbc, 0);
3133 while (delalloc_end < page_end) {
3134 nr_delalloc = find_lock_delalloc_range(inode, tree,
3139 if (nr_delalloc == 0) {
3140 delalloc_start = delalloc_end + 1;
3143 ret = tree->ops->fill_delalloc(inode, page,
3148 /* File system has been set read-only */
3154 * delalloc_end is already one less than the total
3155 * length, so we don't subtract one from
3158 delalloc_to_write += (delalloc_end - delalloc_start +
3161 delalloc_start = delalloc_end + 1;
3163 if (wbc->nr_to_write < delalloc_to_write) {
3166 if (delalloc_to_write < thresh * 2)
3167 thresh = delalloc_to_write;
3168 wbc->nr_to_write = min_t(u64, delalloc_to_write,
3172 /* did the fill delalloc function already unlock and start
3178 * we've unlocked the page, so we can't update
3179 * the mapping's writeback index, just update
3182 wbc->nr_to_write -= nr_written;
3186 if (tree->ops && tree->ops->writepage_start_hook) {
3187 ret = tree->ops->writepage_start_hook(page, start,
3190 /* Fixup worker will requeue */
3192 wbc->pages_skipped++;
3194 redirty_page_for_writepage(wbc, page);
3195 update_nr_written(page, wbc, nr_written);
3203 * we don't want to touch the inode after unlocking the page,
3204 * so we update the mapping writeback index now
3206 update_nr_written(page, wbc, nr_written + 1);
3209 if (last_byte <= start) {
3210 if (tree->ops && tree->ops->writepage_end_io_hook)
3211 tree->ops->writepage_end_io_hook(page, start,
3216 blocksize = inode->i_sb->s_blocksize;
3218 while (cur <= end) {
3219 if (cur >= last_byte) {
3220 if (tree->ops && tree->ops->writepage_end_io_hook)
3221 tree->ops->writepage_end_io_hook(page, cur,
3225 em = epd->get_extent(inode, page, pg_offset, cur,
3227 if (IS_ERR_OR_NULL(em)) {
3232 extent_offset = cur - em->start;
3233 BUG_ON(extent_map_end(em) <= cur);
3235 iosize = min(extent_map_end(em) - cur, end - cur + 1);
3236 iosize = ALIGN(iosize, blocksize);
3237 sector = (em->block_start + extent_offset) >> 9;
3239 block_start = em->block_start;
3240 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
3241 free_extent_map(em);
3245 * compressed and inline extents are written through other
3248 if (compressed || block_start == EXTENT_MAP_HOLE ||
3249 block_start == EXTENT_MAP_INLINE) {
3251 * end_io notification does not happen here for
3252 * compressed extents
3254 if (!compressed && tree->ops &&
3255 tree->ops->writepage_end_io_hook)
3256 tree->ops->writepage_end_io_hook(page, cur,
3259 else if (compressed) {
3260 /* we don't want to end_page_writeback on
3261 * a compressed extent. this happens
3268 pg_offset += iosize;
3271 /* leave this out until we have a page_mkwrite call */
3272 if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
3273 EXTENT_DIRTY, 0, NULL)) {
3275 pg_offset += iosize;
3279 if (tree->ops && tree->ops->writepage_io_hook) {
3280 ret = tree->ops->writepage_io_hook(page, cur,
3288 unsigned long max_nr = end_index + 1;
3290 set_range_writeback(tree, cur, cur + iosize - 1);
3291 if (!PageWriteback(page)) {
3292 printk(KERN_ERR "btrfs warning page %lu not "
3293 "writeback, cur %llu end %llu\n",
3294 page->index, cur, end);
3297 ret = submit_extent_page(write_flags, tree, page,
3298 sector, iosize, pg_offset,
3299 bdev, &epd->bio, max_nr,
3300 end_bio_extent_writepage,
3306 pg_offset += iosize;
3311 /* make sure the mapping tag for page dirty gets cleared */
3312 set_page_writeback(page);
3313 end_page_writeback(page);
3319 /* drop our reference on any cached states */
3320 free_extent_state(cached_state);
3324 static int eb_wait(void *word)
3330 void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
3332 wait_on_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK, eb_wait,
3333 TASK_UNINTERRUPTIBLE);
3336 static int lock_extent_buffer_for_io(struct extent_buffer *eb,
3337 struct btrfs_fs_info *fs_info,
3338 struct extent_page_data *epd)
3340 unsigned long i, num_pages;
3344 if (!btrfs_try_tree_write_lock(eb)) {
3346 flush_write_bio(epd);
3347 btrfs_tree_lock(eb);
3350 if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
3351 btrfs_tree_unlock(eb);
3355 flush_write_bio(epd);
3359 wait_on_extent_buffer_writeback(eb);
3360 btrfs_tree_lock(eb);
3361 if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags))
3363 btrfs_tree_unlock(eb);
3368 * We need to do this to prevent races in people who check if the eb is
3369 * under IO since we can end up having no IO bits set for a short period
3372 spin_lock(&eb->refs_lock);
3373 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3374 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3375 spin_unlock(&eb->refs_lock);
3376 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3377 __percpu_counter_add(&fs_info->dirty_metadata_bytes,
3379 fs_info->dirty_metadata_batch);
3382 spin_unlock(&eb->refs_lock);
3385 btrfs_tree_unlock(eb);
3390 num_pages = num_extent_pages(eb->start, eb->len);
3391 for (i = 0; i < num_pages; i++) {
3392 struct page *p = extent_buffer_page(eb, i);
3394 if (!trylock_page(p)) {
3396 flush_write_bio(epd);
3406 static void end_extent_buffer_writeback(struct extent_buffer *eb)
3408 clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
3409 smp_mb__after_clear_bit();
3410 wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
3413 static void end_bio_extent_buffer_writepage(struct bio *bio, int err)
3415 int uptodate = err == 0;
3416 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
3417 struct extent_buffer *eb;
3421 struct page *page = bvec->bv_page;
3424 eb = (struct extent_buffer *)page->private;
3426 done = atomic_dec_and_test(&eb->io_pages);
3428 if (!uptodate || test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) {
3429 set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3430 ClearPageUptodate(page);
3434 end_page_writeback(page);
3439 end_extent_buffer_writeback(eb);
3440 } while (bvec >= bio->bi_io_vec);
3446 static int write_one_eb(struct extent_buffer *eb,
3447 struct btrfs_fs_info *fs_info,
3448 struct writeback_control *wbc,
3449 struct extent_page_data *epd)
3451 struct block_device *bdev = fs_info->fs_devices->latest_bdev;
3452 u64 offset = eb->start;
3453 unsigned long i, num_pages;
3454 unsigned long bio_flags = 0;
3455 int rw = (epd->sync_io ? WRITE_SYNC : WRITE) | REQ_META;
3458 clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3459 num_pages = num_extent_pages(eb->start, eb->len);
3460 atomic_set(&eb->io_pages, num_pages);
3461 if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
3462 bio_flags = EXTENT_BIO_TREE_LOG;
3464 for (i = 0; i < num_pages; i++) {
3465 struct page *p = extent_buffer_page(eb, i);
3467 clear_page_dirty_for_io(p);
3468 set_page_writeback(p);
3469 ret = submit_extent_page(rw, eb->tree, p, offset >> 9,
3470 PAGE_CACHE_SIZE, 0, bdev, &epd->bio,
3471 -1, end_bio_extent_buffer_writepage,
3472 0, epd->bio_flags, bio_flags);
3473 epd->bio_flags = bio_flags;
3475 set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
3477 if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
3478 end_extent_buffer_writeback(eb);
3482 offset += PAGE_CACHE_SIZE;
3483 update_nr_written(p, wbc, 1);
3487 if (unlikely(ret)) {
3488 for (; i < num_pages; i++) {
3489 struct page *p = extent_buffer_page(eb, i);
3497 int btree_write_cache_pages(struct address_space *mapping,
3498 struct writeback_control *wbc)
3500 struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
3501 struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
3502 struct extent_buffer *eb, *prev_eb = NULL;
3503 struct extent_page_data epd = {
3507 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3512 int nr_to_write_done = 0;
3513 struct pagevec pvec;
3516 pgoff_t end; /* Inclusive */
3520 pagevec_init(&pvec, 0);
3521 if (wbc->range_cyclic) {
3522 index = mapping->writeback_index; /* Start from prev offset */
3525 index = wbc->range_start >> PAGE_CACHE_SHIFT;
3526 end = wbc->range_end >> PAGE_CACHE_SHIFT;
3529 if (wbc->sync_mode == WB_SYNC_ALL)
3530 tag = PAGECACHE_TAG_TOWRITE;
3532 tag = PAGECACHE_TAG_DIRTY;
3534 if (wbc->sync_mode == WB_SYNC_ALL)
3535 tag_pages_for_writeback(mapping, index, end);
3536 while (!done && !nr_to_write_done && (index <= end) &&
3537 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3538 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3542 for (i = 0; i < nr_pages; i++) {
3543 struct page *page = pvec.pages[i];
3545 if (!PagePrivate(page))
3548 if (!wbc->range_cyclic && page->index > end) {
3553 spin_lock(&mapping->private_lock);
3554 if (!PagePrivate(page)) {
3555 spin_unlock(&mapping->private_lock);
3559 eb = (struct extent_buffer *)page->private;
3562 * Shouldn't happen and normally this would be a BUG_ON
3563 * but no sense in crashing the users box for something
3564 * we can survive anyway.
3567 spin_unlock(&mapping->private_lock);
3572 if (eb == prev_eb) {
3573 spin_unlock(&mapping->private_lock);
3577 ret = atomic_inc_not_zero(&eb->refs);
3578 spin_unlock(&mapping->private_lock);
3583 ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
3585 free_extent_buffer(eb);
3589 ret = write_one_eb(eb, fs_info, wbc, &epd);
3592 free_extent_buffer(eb);
3595 free_extent_buffer(eb);
3598 * the filesystem may choose to bump up nr_to_write.
3599 * We have to make sure to honor the new nr_to_write
3602 nr_to_write_done = wbc->nr_to_write <= 0;
3604 pagevec_release(&pvec);
3607 if (!scanned && !done) {
3609 * We hit the last page and there is more work to be done: wrap
3610 * back to the start of the file
3616 flush_write_bio(&epd);
3621 * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
3622 * @mapping: address space structure to write
3623 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
3624 * @writepage: function called for each page
3625 * @data: data passed to writepage function
3627 * If a page is already under I/O, write_cache_pages() skips it, even
3628 * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
3629 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
3630 * and msync() need to guarantee that all the data which was dirty at the time
3631 * the call was made get new I/O started against them. If wbc->sync_mode is
3632 * WB_SYNC_ALL then we were called for data integrity and we must wait for
3633 * existing IO to complete.
3635 static int extent_write_cache_pages(struct extent_io_tree *tree,
3636 struct address_space *mapping,
3637 struct writeback_control *wbc,
3638 writepage_t writepage, void *data,
3639 void (*flush_fn)(void *))
3641 struct inode *inode = mapping->host;
3644 int nr_to_write_done = 0;
3645 struct pagevec pvec;
3648 pgoff_t end; /* Inclusive */
3653 * We have to hold onto the inode so that ordered extents can do their
3654 * work when the IO finishes. The alternative to this is failing to add
3655 * an ordered extent if the igrab() fails there and that is a huge pain
3656 * to deal with, so instead just hold onto the inode throughout the
3657 * writepages operation. If it fails here we are freeing up the inode
3658 * anyway and we'd rather not waste our time writing out stuff that is
3659 * going to be truncated anyway.
3664 pagevec_init(&pvec, 0);
3665 if (wbc->range_cyclic) {
3666 index = mapping->writeback_index; /* Start from prev offset */
3669 index = wbc->range_start >> PAGE_CACHE_SHIFT;
3670 end = wbc->range_end >> PAGE_CACHE_SHIFT;
3673 if (wbc->sync_mode == WB_SYNC_ALL)
3674 tag = PAGECACHE_TAG_TOWRITE;
3676 tag = PAGECACHE_TAG_DIRTY;
3678 if (wbc->sync_mode == WB_SYNC_ALL)
3679 tag_pages_for_writeback(mapping, index, end);
3680 while (!done && !nr_to_write_done && (index <= end) &&
3681 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
3682 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
3686 for (i = 0; i < nr_pages; i++) {
3687 struct page *page = pvec.pages[i];
3690 * At this point we hold neither mapping->tree_lock nor
3691 * lock on the page itself: the page may be truncated or
3692 * invalidated (changing page->mapping to NULL), or even
3693 * swizzled back from swapper_space to tmpfs file
3696 if (!trylock_page(page)) {
3701 if (unlikely(page->mapping != mapping)) {
3706 if (!wbc->range_cyclic && page->index > end) {
3712 if (wbc->sync_mode != WB_SYNC_NONE) {
3713 if (PageWriteback(page))
3715 wait_on_page_writeback(page);
3718 if (PageWriteback(page) ||
3719 !clear_page_dirty_for_io(page)) {
3724 ret = (*writepage)(page, wbc, data);
3726 if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
3734 * the filesystem may choose to bump up nr_to_write.
3735 * We have to make sure to honor the new nr_to_write
3738 nr_to_write_done = wbc->nr_to_write <= 0;
3740 pagevec_release(&pvec);
3743 if (!scanned && !done) {
3745 * We hit the last page and there is more work to be done: wrap
3746 * back to the start of the file
3752 btrfs_add_delayed_iput(inode);
3756 static void flush_epd_write_bio(struct extent_page_data *epd)
3765 ret = submit_one_bio(rw, epd->bio, 0, epd->bio_flags);
3766 BUG_ON(ret < 0); /* -ENOMEM */
3771 static noinline void flush_write_bio(void *data)
3773 struct extent_page_data *epd = data;
3774 flush_epd_write_bio(epd);
3777 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
3778 get_extent_t *get_extent,
3779 struct writeback_control *wbc)
3782 struct extent_page_data epd = {
3785 .get_extent = get_extent,
3787 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3791 ret = __extent_writepage(page, wbc, &epd);
3793 flush_epd_write_bio(&epd);
3797 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
3798 u64 start, u64 end, get_extent_t *get_extent,
3802 struct address_space *mapping = inode->i_mapping;
3804 unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
3807 struct extent_page_data epd = {
3810 .get_extent = get_extent,
3812 .sync_io = mode == WB_SYNC_ALL,
3815 struct writeback_control wbc_writepages = {
3817 .nr_to_write = nr_pages * 2,
3818 .range_start = start,
3819 .range_end = end + 1,
3822 while (start <= end) {
3823 page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
3824 if (clear_page_dirty_for_io(page))
3825 ret = __extent_writepage(page, &wbc_writepages, &epd);
3827 if (tree->ops && tree->ops->writepage_end_io_hook)
3828 tree->ops->writepage_end_io_hook(page, start,
3829 start + PAGE_CACHE_SIZE - 1,
3833 page_cache_release(page);
3834 start += PAGE_CACHE_SIZE;
3837 flush_epd_write_bio(&epd);
3841 int extent_writepages(struct extent_io_tree *tree,
3842 struct address_space *mapping,
3843 get_extent_t *get_extent,
3844 struct writeback_control *wbc)
3847 struct extent_page_data epd = {
3850 .get_extent = get_extent,
3852 .sync_io = wbc->sync_mode == WB_SYNC_ALL,
3856 ret = extent_write_cache_pages(tree, mapping, wbc,
3857 __extent_writepage, &epd,
3859 flush_epd_write_bio(&epd);
3863 int extent_readpages(struct extent_io_tree *tree,
3864 struct address_space *mapping,
3865 struct list_head *pages, unsigned nr_pages,
3866 get_extent_t get_extent)
3868 struct bio *bio = NULL;
3870 unsigned long bio_flags = 0;
3871 struct page *pagepool[16];
3873 struct extent_map *em_cached = NULL;
3876 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
3877 page = list_entry(pages->prev, struct page, lru);
3879 prefetchw(&page->flags);
3880 list_del(&page->lru);
3881 if (add_to_page_cache_lru(page, mapping,
3882 page->index, GFP_NOFS)) {
3883 page_cache_release(page);
3887 pagepool[nr++] = page;
3888 if (nr < ARRAY_SIZE(pagepool))
3890 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
3891 &bio, 0, &bio_flags, READ);
3895 __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
3896 &bio, 0, &bio_flags, READ);
3899 free_extent_map(em_cached);
3901 BUG_ON(!list_empty(pages));
3903 return submit_one_bio(READ, bio, 0, bio_flags);
3908 * basic invalidatepage code, this waits on any locked or writeback
3909 * ranges corresponding to the page, and then deletes any extent state
3910 * records from the tree
3912 int extent_invalidatepage(struct extent_io_tree *tree,
3913 struct page *page, unsigned long offset)
3915 struct extent_state *cached_state = NULL;
3916 u64 start = page_offset(page);
3917 u64 end = start + PAGE_CACHE_SIZE - 1;
3918 size_t blocksize = page->mapping->host->i_sb->s_blocksize;
3920 start += ALIGN(offset, blocksize);
3924 lock_extent_bits(tree, start, end, 0, &cached_state);
3925 wait_on_page_writeback(page);
3926 clear_extent_bit(tree, start, end,
3927 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
3928 EXTENT_DO_ACCOUNTING,
3929 1, 1, &cached_state, GFP_NOFS);
3934 * a helper for releasepage, this tests for areas of the page that
3935 * are locked or under IO and drops the related state bits if it is safe
3938 static int try_release_extent_state(struct extent_map_tree *map,
3939 struct extent_io_tree *tree,
3940 struct page *page, gfp_t mask)
3942 u64 start = page_offset(page);
3943 u64 end = start + PAGE_CACHE_SIZE - 1;
3946 if (test_range_bit(tree, start, end,
3947 EXTENT_IOBITS, 0, NULL))
3950 if ((mask & GFP_NOFS) == GFP_NOFS)
3953 * at this point we can safely clear everything except the
3954 * locked bit and the nodatasum bit
3956 ret = clear_extent_bit(tree, start, end,
3957 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
3960 /* if clear_extent_bit failed for enomem reasons,
3961 * we can't allow the release to continue.
3972 * a helper for releasepage. As long as there are no locked extents
3973 * in the range corresponding to the page, both state records and extent
3974 * map records are removed
3976 int try_release_extent_mapping(struct extent_map_tree *map,
3977 struct extent_io_tree *tree, struct page *page,
3980 struct extent_map *em;
3981 u64 start = page_offset(page);
3982 u64 end = start + PAGE_CACHE_SIZE - 1;
3984 if ((mask & __GFP_WAIT) &&
3985 page->mapping->host->i_size > 16 * 1024 * 1024) {
3987 while (start <= end) {
3988 len = end - start + 1;
3989 write_lock(&map->lock);
3990 em = lookup_extent_mapping(map, start, len);
3992 write_unlock(&map->lock);
3995 if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
3996 em->start != start) {
3997 write_unlock(&map->lock);
3998 free_extent_map(em);
4001 if (!test_range_bit(tree, em->start,
4002 extent_map_end(em) - 1,
4003 EXTENT_LOCKED | EXTENT_WRITEBACK,
4005 remove_extent_mapping(map, em);
4006 /* once for the rb tree */
4007 free_extent_map(em);
4009 start = extent_map_end(em);
4010 write_unlock(&map->lock);
4013 free_extent_map(em);
4016 return try_release_extent_state(map, tree, page, mask);
4020 * helper function for fiemap, which doesn't want to see any holes.
4021 * This maps until we find something past 'last'
4023 static struct extent_map *get_extent_skip_holes(struct inode *inode,
4026 get_extent_t *get_extent)
4028 u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
4029 struct extent_map *em;
4036 len = last - offset;
4039 len = ALIGN(len, sectorsize);
4040 em = get_extent(inode, NULL, 0, offset, len, 0);
4041 if (IS_ERR_OR_NULL(em))
4044 /* if this isn't a hole return it */
4045 if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
4046 em->block_start != EXTENT_MAP_HOLE) {
4050 /* this is a hole, advance to the next extent */
4051 offset = extent_map_end(em);
4052 free_extent_map(em);
4059 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4060 __u64 start, __u64 len, get_extent_t *get_extent)
4064 u64 max = start + len;
4068 u64 last_for_get_extent = 0;
4070 u64 isize = i_size_read(inode);
4071 struct btrfs_key found_key;
4072 struct extent_map *em = NULL;
4073 struct extent_state *cached_state = NULL;
4074 struct btrfs_path *path;
4075 struct btrfs_file_extent_item *item;
4080 unsigned long emflags;
4085 path = btrfs_alloc_path();
4088 path->leave_spinning = 1;
4090 start = ALIGN(start, BTRFS_I(inode)->root->sectorsize);
4091 len = ALIGN(len, BTRFS_I(inode)->root->sectorsize);
4094 * lookup the last file extent. We're not using i_size here
4095 * because there might be preallocation past i_size
4097 ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
4098 path, btrfs_ino(inode), -1, 0);
4100 btrfs_free_path(path);
4105 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
4106 struct btrfs_file_extent_item);
4107 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
4108 found_type = btrfs_key_type(&found_key);
4110 /* No extents, but there might be delalloc bits */
4111 if (found_key.objectid != btrfs_ino(inode) ||
4112 found_type != BTRFS_EXTENT_DATA_KEY) {
4113 /* have to trust i_size as the end */
4115 last_for_get_extent = isize;
4118 * remember the start of the last extent. There are a
4119 * bunch of different factors that go into the length of the
4120 * extent, so its much less complex to remember where it started
4122 last = found_key.offset;
4123 last_for_get_extent = last + 1;
4125 btrfs_free_path(path);
4128 * we might have some extents allocated but more delalloc past those
4129 * extents. so, we trust isize unless the start of the last extent is
4134 last_for_get_extent = isize;
4137 lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1, 0,
4140 em = get_extent_skip_holes(inode, start, last_for_get_extent,
4150 u64 offset_in_extent = 0;
4152 /* break if the extent we found is outside the range */
4153 if (em->start >= max || extent_map_end(em) < off)
4157 * get_extent may return an extent that starts before our
4158 * requested range. We have to make sure the ranges
4159 * we return to fiemap always move forward and don't
4160 * overlap, so adjust the offsets here
4162 em_start = max(em->start, off);
4165 * record the offset from the start of the extent
4166 * for adjusting the disk offset below. Only do this if the
4167 * extent isn't compressed since our in ram offset may be past
4168 * what we have actually allocated on disk.
4170 if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4171 offset_in_extent = em_start - em->start;
4172 em_end = extent_map_end(em);
4173 em_len = em_end - em_start;
4174 emflags = em->flags;
4179 * bump off for our next call to get_extent
4181 off = extent_map_end(em);
4185 if (em->block_start == EXTENT_MAP_LAST_BYTE) {
4187 flags |= FIEMAP_EXTENT_LAST;
4188 } else if (em->block_start == EXTENT_MAP_INLINE) {
4189 flags |= (FIEMAP_EXTENT_DATA_INLINE |
4190 FIEMAP_EXTENT_NOT_ALIGNED);
4191 } else if (em->block_start == EXTENT_MAP_DELALLOC) {
4192 flags |= (FIEMAP_EXTENT_DELALLOC |
4193 FIEMAP_EXTENT_UNKNOWN);
4195 disko = em->block_start + offset_in_extent;
4197 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
4198 flags |= FIEMAP_EXTENT_ENCODED;
4200 free_extent_map(em);
4202 if ((em_start >= last) || em_len == (u64)-1 ||
4203 (last == (u64)-1 && isize <= em_end)) {
4204 flags |= FIEMAP_EXTENT_LAST;
4208 /* now scan forward to see if this is really the last extent. */
4209 em = get_extent_skip_holes(inode, off, last_for_get_extent,
4216 flags |= FIEMAP_EXTENT_LAST;
4219 ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
4225 free_extent_map(em);
4227 unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
4228 &cached_state, GFP_NOFS);
4232 static void __free_extent_buffer(struct extent_buffer *eb)
4234 btrfs_leak_debug_del(&eb->leak_list);
4235 kmem_cache_free(extent_buffer_cache, eb);
4238 static int extent_buffer_under_io(struct extent_buffer *eb)
4240 return (atomic_read(&eb->io_pages) ||
4241 test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
4242 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4246 * Helper for releasing extent buffer page.
4248 static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
4249 unsigned long start_idx)
4251 unsigned long index;
4252 unsigned long num_pages;
4254 int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4256 BUG_ON(extent_buffer_under_io(eb));
4258 num_pages = num_extent_pages(eb->start, eb->len);
4259 index = start_idx + num_pages;
4260 if (start_idx >= index)
4265 page = extent_buffer_page(eb, index);
4266 if (page && mapped) {
4267 spin_lock(&page->mapping->private_lock);
4269 * We do this since we'll remove the pages after we've
4270 * removed the eb from the radix tree, so we could race
4271 * and have this page now attached to the new eb. So
4272 * only clear page_private if it's still connected to
4275 if (PagePrivate(page) &&
4276 page->private == (unsigned long)eb) {
4277 BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
4278 BUG_ON(PageDirty(page));
4279 BUG_ON(PageWriteback(page));
4281 * We need to make sure we haven't be attached
4284 ClearPagePrivate(page);
4285 set_page_private(page, 0);
4286 /* One for the page private */
4287 page_cache_release(page);
4289 spin_unlock(&page->mapping->private_lock);
4293 /* One for when we alloced the page */
4294 page_cache_release(page);
4296 } while (index != start_idx);
4300 * Helper for releasing the extent buffer.
4302 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
4304 btrfs_release_extent_buffer_page(eb, 0);
4305 __free_extent_buffer(eb);
4308 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
4313 struct extent_buffer *eb = NULL;
4315 eb = kmem_cache_zalloc(extent_buffer_cache, mask);
4322 rwlock_init(&eb->lock);
4323 atomic_set(&eb->write_locks, 0);
4324 atomic_set(&eb->read_locks, 0);
4325 atomic_set(&eb->blocking_readers, 0);
4326 atomic_set(&eb->blocking_writers, 0);
4327 atomic_set(&eb->spinning_readers, 0);
4328 atomic_set(&eb->spinning_writers, 0);
4329 eb->lock_nested = 0;
4330 init_waitqueue_head(&eb->write_lock_wq);
4331 init_waitqueue_head(&eb->read_lock_wq);
4333 btrfs_leak_debug_add(&eb->leak_list, &buffers);
4335 spin_lock_init(&eb->refs_lock);
4336 atomic_set(&eb->refs, 1);
4337 atomic_set(&eb->io_pages, 0);
4340 * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
4342 BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
4343 > MAX_INLINE_EXTENT_BUFFER_SIZE);
4344 BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
4349 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
4353 struct extent_buffer *new;
4354 unsigned long num_pages = num_extent_pages(src->start, src->len);
4356 new = __alloc_extent_buffer(NULL, src->start, src->len, GFP_NOFS);
4360 for (i = 0; i < num_pages; i++) {
4361 p = alloc_page(GFP_NOFS);
4363 btrfs_release_extent_buffer(new);
4366 attach_extent_buffer_page(new, p);
4367 WARN_ON(PageDirty(p));
4372 copy_extent_buffer(new, src, 0, 0, src->len);
4373 set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
4374 set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
4379 struct extent_buffer *alloc_dummy_extent_buffer(u64 start, unsigned long len)
4381 struct extent_buffer *eb;
4382 unsigned long num_pages = num_extent_pages(0, len);
4385 eb = __alloc_extent_buffer(NULL, start, len, GFP_NOFS);
4389 for (i = 0; i < num_pages; i++) {
4390 eb->pages[i] = alloc_page(GFP_NOFS);
4394 set_extent_buffer_uptodate(eb);
4395 btrfs_set_header_nritems(eb, 0);
4396 set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
4401 __free_page(eb->pages[i - 1]);
4402 __free_extent_buffer(eb);
4406 static void check_buffer_tree_ref(struct extent_buffer *eb)
4409 /* the ref bit is tricky. We have to make sure it is set
4410 * if we have the buffer dirty. Otherwise the
4411 * code to free a buffer can end up dropping a dirty
4414 * Once the ref bit is set, it won't go away while the
4415 * buffer is dirty or in writeback, and it also won't
4416 * go away while we have the reference count on the
4419 * We can't just set the ref bit without bumping the
4420 * ref on the eb because free_extent_buffer might
4421 * see the ref bit and try to clear it. If this happens
4422 * free_extent_buffer might end up dropping our original
4423 * ref by mistake and freeing the page before we are able
4424 * to add one more ref.
4426 * So bump the ref count first, then set the bit. If someone
4427 * beat us to it, drop the ref we added.
4429 refs = atomic_read(&eb->refs);
4430 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4433 spin_lock(&eb->refs_lock);
4434 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4435 atomic_inc(&eb->refs);
4436 spin_unlock(&eb->refs_lock);
4439 static void mark_extent_buffer_accessed(struct extent_buffer *eb)
4441 unsigned long num_pages, i;
4443 check_buffer_tree_ref(eb);
4445 num_pages = num_extent_pages(eb->start, eb->len);
4446 for (i = 0; i < num_pages; i++) {
4447 struct page *p = extent_buffer_page(eb, i);
4448 mark_page_accessed(p);
4452 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
4453 u64 start, unsigned long len)
4455 unsigned long num_pages = num_extent_pages(start, len);
4457 unsigned long index = start >> PAGE_CACHE_SHIFT;
4458 struct extent_buffer *eb;
4459 struct extent_buffer *exists = NULL;
4461 struct address_space *mapping = tree->mapping;
4466 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4467 if (eb && atomic_inc_not_zero(&eb->refs)) {
4469 mark_extent_buffer_accessed(eb);
4474 eb = __alloc_extent_buffer(tree, start, len, GFP_NOFS);
4478 for (i = 0; i < num_pages; i++, index++) {
4479 p = find_or_create_page(mapping, index, GFP_NOFS);
4483 spin_lock(&mapping->private_lock);
4484 if (PagePrivate(p)) {
4486 * We could have already allocated an eb for this page
4487 * and attached one so lets see if we can get a ref on
4488 * the existing eb, and if we can we know it's good and
4489 * we can just return that one, else we know we can just
4490 * overwrite page->private.
4492 exists = (struct extent_buffer *)p->private;
4493 if (atomic_inc_not_zero(&exists->refs)) {
4494 spin_unlock(&mapping->private_lock);
4496 page_cache_release(p);
4497 mark_extent_buffer_accessed(exists);
4502 * Do this so attach doesn't complain and we need to
4503 * drop the ref the old guy had.
4505 ClearPagePrivate(p);
4506 WARN_ON(PageDirty(p));
4507 page_cache_release(p);
4509 attach_extent_buffer_page(eb, p);
4510 spin_unlock(&mapping->private_lock);
4511 WARN_ON(PageDirty(p));
4512 mark_page_accessed(p);
4514 if (!PageUptodate(p))
4518 * see below about how we avoid a nasty race with release page
4519 * and why we unlock later
4523 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4525 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
4529 spin_lock(&tree->buffer_lock);
4530 ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
4531 if (ret == -EEXIST) {
4532 exists = radix_tree_lookup(&tree->buffer,
4533 start >> PAGE_CACHE_SHIFT);
4534 if (!atomic_inc_not_zero(&exists->refs)) {
4535 spin_unlock(&tree->buffer_lock);
4536 radix_tree_preload_end();
4540 spin_unlock(&tree->buffer_lock);
4541 radix_tree_preload_end();
4542 mark_extent_buffer_accessed(exists);
4545 /* add one reference for the tree */
4546 check_buffer_tree_ref(eb);
4547 spin_unlock(&tree->buffer_lock);
4548 radix_tree_preload_end();
4551 * there is a race where release page may have
4552 * tried to find this extent buffer in the radix
4553 * but failed. It will tell the VM it is safe to
4554 * reclaim the, and it will clear the page private bit.
4555 * We must make sure to set the page private bit properly
4556 * after the extent buffer is in the radix tree so
4557 * it doesn't get lost
4559 SetPageChecked(eb->pages[0]);
4560 for (i = 1; i < num_pages; i++) {
4561 p = extent_buffer_page(eb, i);
4562 ClearPageChecked(p);
4565 unlock_page(eb->pages[0]);
4569 for (i = 0; i < num_pages; i++) {
4571 unlock_page(eb->pages[i]);
4574 WARN_ON(!atomic_dec_and_test(&eb->refs));
4575 btrfs_release_extent_buffer(eb);
4579 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
4580 u64 start, unsigned long len)
4582 struct extent_buffer *eb;
4585 eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
4586 if (eb && atomic_inc_not_zero(&eb->refs)) {
4588 mark_extent_buffer_accessed(eb);
4596 static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
4598 struct extent_buffer *eb =
4599 container_of(head, struct extent_buffer, rcu_head);
4601 __free_extent_buffer(eb);
4604 /* Expects to have eb->eb_lock already held */
4605 static int release_extent_buffer(struct extent_buffer *eb)
4607 WARN_ON(atomic_read(&eb->refs) == 0);
4608 if (atomic_dec_and_test(&eb->refs)) {
4609 if (test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags)) {
4610 spin_unlock(&eb->refs_lock);
4612 struct extent_io_tree *tree = eb->tree;
4614 spin_unlock(&eb->refs_lock);
4616 spin_lock(&tree->buffer_lock);
4617 radix_tree_delete(&tree->buffer,
4618 eb->start >> PAGE_CACHE_SHIFT);
4619 spin_unlock(&tree->buffer_lock);
4622 /* Should be safe to release our pages at this point */
4623 btrfs_release_extent_buffer_page(eb, 0);
4624 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
4627 spin_unlock(&eb->refs_lock);
4632 void free_extent_buffer(struct extent_buffer *eb)
4640 refs = atomic_read(&eb->refs);
4643 old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
4648 spin_lock(&eb->refs_lock);
4649 if (atomic_read(&eb->refs) == 2 &&
4650 test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
4651 atomic_dec(&eb->refs);
4653 if (atomic_read(&eb->refs) == 2 &&
4654 test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
4655 !extent_buffer_under_io(eb) &&
4656 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4657 atomic_dec(&eb->refs);
4660 * I know this is terrible, but it's temporary until we stop tracking
4661 * the uptodate bits and such for the extent buffers.
4663 release_extent_buffer(eb);
4666 void free_extent_buffer_stale(struct extent_buffer *eb)
4671 spin_lock(&eb->refs_lock);
4672 set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
4674 if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
4675 test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
4676 atomic_dec(&eb->refs);
4677 release_extent_buffer(eb);
4680 void clear_extent_buffer_dirty(struct extent_buffer *eb)
4683 unsigned long num_pages;
4686 num_pages = num_extent_pages(eb->start, eb->len);
4688 for (i = 0; i < num_pages; i++) {
4689 page = extent_buffer_page(eb, i);
4690 if (!PageDirty(page))
4694 WARN_ON(!PagePrivate(page));
4696 clear_page_dirty_for_io(page);
4697 spin_lock_irq(&page->mapping->tree_lock);
4698 if (!PageDirty(page)) {
4699 radix_tree_tag_clear(&page->mapping->page_tree,
4701 PAGECACHE_TAG_DIRTY);
4703 spin_unlock_irq(&page->mapping->tree_lock);
4704 ClearPageError(page);
4707 WARN_ON(atomic_read(&eb->refs) == 0);
4710 int set_extent_buffer_dirty(struct extent_buffer *eb)
4713 unsigned long num_pages;
4716 check_buffer_tree_ref(eb);
4718 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
4720 num_pages = num_extent_pages(eb->start, eb->len);
4721 WARN_ON(atomic_read(&eb->refs) == 0);
4722 WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
4724 for (i = 0; i < num_pages; i++)
4725 set_page_dirty(extent_buffer_page(eb, i));
4729 int clear_extent_buffer_uptodate(struct extent_buffer *eb)
4733 unsigned long num_pages;
4735 clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4736 num_pages = num_extent_pages(eb->start, eb->len);
4737 for (i = 0; i < num_pages; i++) {
4738 page = extent_buffer_page(eb, i);
4740 ClearPageUptodate(page);
4745 int set_extent_buffer_uptodate(struct extent_buffer *eb)
4749 unsigned long num_pages;
4751 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4752 num_pages = num_extent_pages(eb->start, eb->len);
4753 for (i = 0; i < num_pages; i++) {
4754 page = extent_buffer_page(eb, i);
4755 SetPageUptodate(page);
4760 int extent_buffer_uptodate(struct extent_buffer *eb)
4762 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4765 int read_extent_buffer_pages(struct extent_io_tree *tree,
4766 struct extent_buffer *eb, u64 start, int wait,
4767 get_extent_t *get_extent, int mirror_num)
4770 unsigned long start_i;
4774 int locked_pages = 0;
4775 int all_uptodate = 1;
4776 unsigned long num_pages;
4777 unsigned long num_reads = 0;
4778 struct bio *bio = NULL;
4779 unsigned long bio_flags = 0;
4781 if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
4785 WARN_ON(start < eb->start);
4786 start_i = (start >> PAGE_CACHE_SHIFT) -
4787 (eb->start >> PAGE_CACHE_SHIFT);
4792 num_pages = num_extent_pages(eb->start, eb->len);
4793 for (i = start_i; i < num_pages; i++) {
4794 page = extent_buffer_page(eb, i);
4795 if (wait == WAIT_NONE) {
4796 if (!trylock_page(page))
4802 if (!PageUptodate(page)) {
4809 set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
4813 clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
4814 eb->read_mirror = 0;
4815 atomic_set(&eb->io_pages, num_reads);
4816 for (i = start_i; i < num_pages; i++) {
4817 page = extent_buffer_page(eb, i);
4818 if (!PageUptodate(page)) {
4819 ClearPageError(page);
4820 err = __extent_read_full_page(tree, page,
4822 mirror_num, &bio_flags,
4832 err = submit_one_bio(READ | REQ_META, bio, mirror_num,
4838 if (ret || wait != WAIT_COMPLETE)
4841 for (i = start_i; i < num_pages; i++) {
4842 page = extent_buffer_page(eb, i);
4843 wait_on_page_locked(page);
4844 if (!PageUptodate(page))
4852 while (locked_pages > 0) {
4853 page = extent_buffer_page(eb, i);
4861 void read_extent_buffer(struct extent_buffer *eb, void *dstv,
4862 unsigned long start,
4869 char *dst = (char *)dstv;
4870 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4871 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4873 WARN_ON(start > eb->len);
4874 WARN_ON(start + len > eb->start + eb->len);
4876 offset = (start_offset + start) & (PAGE_CACHE_SIZE - 1);
4879 page = extent_buffer_page(eb, i);
4881 cur = min(len, (PAGE_CACHE_SIZE - offset));
4882 kaddr = page_address(page);
4883 memcpy(dst, kaddr + offset, cur);
4892 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
4893 unsigned long min_len, char **map,
4894 unsigned long *map_start,
4895 unsigned long *map_len)
4897 size_t offset = start & (PAGE_CACHE_SIZE - 1);
4900 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4901 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4902 unsigned long end_i = (start_offset + start + min_len - 1) >>
4909 offset = start_offset;
4913 *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
4916 if (start + min_len > eb->len) {
4917 WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
4919 eb->start, eb->len, start, min_len);
4923 p = extent_buffer_page(eb, i);
4924 kaddr = page_address(p);
4925 *map = kaddr + offset;
4926 *map_len = PAGE_CACHE_SIZE - offset;
4930 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
4931 unsigned long start,
4938 char *ptr = (char *)ptrv;
4939 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4940 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4943 WARN_ON(start > eb->len);
4944 WARN_ON(start + len > eb->start + eb->len);
4946 offset = (start_offset + start) & (PAGE_CACHE_SIZE - 1);
4949 page = extent_buffer_page(eb, i);
4951 cur = min(len, (PAGE_CACHE_SIZE - offset));
4953 kaddr = page_address(page);
4954 ret = memcmp(ptr, kaddr + offset, cur);
4966 void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
4967 unsigned long start, unsigned long len)
4973 char *src = (char *)srcv;
4974 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
4975 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
4977 WARN_ON(start > eb->len);
4978 WARN_ON(start + len > eb->start + eb->len);
4980 offset = (start_offset + start) & (PAGE_CACHE_SIZE - 1);
4983 page = extent_buffer_page(eb, i);
4984 WARN_ON(!PageUptodate(page));
4986 cur = min(len, PAGE_CACHE_SIZE - offset);
4987 kaddr = page_address(page);
4988 memcpy(kaddr + offset, src, cur);
4997 void memset_extent_buffer(struct extent_buffer *eb, char c,
4998 unsigned long start, unsigned long len)
5004 size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
5005 unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
5007 WARN_ON(start > eb->len);
5008 WARN_ON(start + len > eb->start + eb->len);
5010 offset = (start_offset + start) & (PAGE_CACHE_SIZE - 1);
5013 page = extent_buffer_page(eb, i);
5014 WARN_ON(!PageUptodate(page));
5016 cur = min(len, PAGE_CACHE_SIZE - offset);
5017 kaddr = page_address(page);
5018 memset(kaddr + offset, c, cur);
5026 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
5027 unsigned long dst_offset, unsigned long src_offset,
5030 u64 dst_len = dst->len;
5035 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
5036 unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
5038 WARN_ON(src->len != dst_len);
5040 offset = (start_offset + dst_offset) &
5041 (PAGE_CACHE_SIZE - 1);
5044 page = extent_buffer_page(dst, i);
5045 WARN_ON(!PageUptodate(page));
5047 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
5049 kaddr = page_address(page);
5050 read_extent_buffer(src, kaddr + offset, src_offset, cur);
5059 static void move_pages(struct page *dst_page, struct page *src_page,
5060 unsigned long dst_off, unsigned long src_off,
5063 char *dst_kaddr = page_address(dst_page);
5064 if (dst_page == src_page) {
5065 memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
5067 char *src_kaddr = page_address(src_page);
5068 char *p = dst_kaddr + dst_off + len;
5069 char *s = src_kaddr + src_off + len;
5076 static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
5078 unsigned long distance = (src > dst) ? src - dst : dst - src;
5079 return distance < len;
5082 static void copy_pages(struct page *dst_page, struct page *src_page,
5083 unsigned long dst_off, unsigned long src_off,
5086 char *dst_kaddr = page_address(dst_page);
5088 int must_memmove = 0;
5090 if (dst_page != src_page) {
5091 src_kaddr = page_address(src_page);
5093 src_kaddr = dst_kaddr;
5094 if (areas_overlap(src_off, dst_off, len))
5099 memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
5101 memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
5104 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5105 unsigned long src_offset, unsigned long len)
5108 size_t dst_off_in_page;
5109 size_t src_off_in_page;
5110 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
5111 unsigned long dst_i;
5112 unsigned long src_i;
5114 if (src_offset + len > dst->len) {
5115 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
5116 "len %lu dst len %lu\n", src_offset, len, dst->len);
5119 if (dst_offset + len > dst->len) {
5120 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
5121 "len %lu dst len %lu\n", dst_offset, len, dst->len);
5126 dst_off_in_page = (start_offset + dst_offset) &
5127 (PAGE_CACHE_SIZE - 1);
5128 src_off_in_page = (start_offset + src_offset) &
5129 (PAGE_CACHE_SIZE - 1);
5131 dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
5132 src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
5134 cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
5136 cur = min_t(unsigned long, cur,
5137 (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
5139 copy_pages(extent_buffer_page(dst, dst_i),
5140 extent_buffer_page(dst, src_i),
5141 dst_off_in_page, src_off_in_page, cur);
5149 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
5150 unsigned long src_offset, unsigned long len)
5153 size_t dst_off_in_page;
5154 size_t src_off_in_page;
5155 unsigned long dst_end = dst_offset + len - 1;
5156 unsigned long src_end = src_offset + len - 1;
5157 size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
5158 unsigned long dst_i;
5159 unsigned long src_i;
5161 if (src_offset + len > dst->len) {
5162 printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
5163 "len %lu len %lu\n", src_offset, len, dst->len);
5166 if (dst_offset + len > dst->len) {
5167 printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
5168 "len %lu len %lu\n", dst_offset, len, dst->len);
5171 if (dst_offset < src_offset) {
5172 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
5176 dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
5177 src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
5179 dst_off_in_page = (start_offset + dst_end) &
5180 (PAGE_CACHE_SIZE - 1);
5181 src_off_in_page = (start_offset + src_end) &
5182 (PAGE_CACHE_SIZE - 1);
5184 cur = min_t(unsigned long, len, src_off_in_page + 1);
5185 cur = min(cur, dst_off_in_page + 1);
5186 move_pages(extent_buffer_page(dst, dst_i),
5187 extent_buffer_page(dst, src_i),
5188 dst_off_in_page - cur + 1,
5189 src_off_in_page - cur + 1, cur);
5197 int try_release_extent_buffer(struct page *page)
5199 struct extent_buffer *eb;
5202 * We need to make sure noboody is attaching this page to an eb right
5205 spin_lock(&page->mapping->private_lock);
5206 if (!PagePrivate(page)) {
5207 spin_unlock(&page->mapping->private_lock);
5211 eb = (struct extent_buffer *)page->private;
5215 * This is a little awful but should be ok, we need to make sure that
5216 * the eb doesn't disappear out from under us while we're looking at
5219 spin_lock(&eb->refs_lock);
5220 if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
5221 spin_unlock(&eb->refs_lock);
5222 spin_unlock(&page->mapping->private_lock);
5225 spin_unlock(&page->mapping->private_lock);
5228 * If tree ref isn't set then we know the ref on this eb is a real ref,
5229 * so just return, this page will likely be freed soon anyway.
5231 if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
5232 spin_unlock(&eb->refs_lock);
5236 return release_extent_buffer(eb);