Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#include <linux/slab.h>
7#include <linux/blkdev.h>
8#include <linux/writeback.h>
9#include <linux/sched/mm.h>
10#include "misc.h"
11#include "ctree.h"
12#include "transaction.h"
13#include "btrfs_inode.h"
14#include "extent_io.h"
15#include "disk-io.h"
16#include "compression.h"
17#include "delalloc-space.h"
18
19static struct kmem_cache *btrfs_ordered_extent_cache;
20
21static u64 entry_end(struct btrfs_ordered_extent *entry)
22{
23 if (entry->file_offset + entry->len < entry->file_offset)
24 return (u64)-1;
25 return entry->file_offset + entry->len;
26}
27
28/* returns NULL if the insertion worked, or it returns the node it did find
29 * in the tree
30 */
31static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
32 struct rb_node *node)
33{
34 struct rb_node **p = &root->rb_node;
35 struct rb_node *parent = NULL;
36 struct btrfs_ordered_extent *entry;
37
38 while (*p) {
39 parent = *p;
40 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
41
42 if (file_offset < entry->file_offset)
43 p = &(*p)->rb_left;
44 else if (file_offset >= entry_end(entry))
45 p = &(*p)->rb_right;
46 else
47 return parent;
48 }
49
50 rb_link_node(node, parent, p);
51 rb_insert_color(node, root);
52 return NULL;
53}
54
55static void ordered_data_tree_panic(struct inode *inode, int errno,
56 u64 offset)
57{
58 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
59 btrfs_panic(fs_info, errno,
60 "Inconsistency in ordered tree at offset %llu", offset);
61}
62
63/*
64 * look for a given offset in the tree, and if it can't be found return the
65 * first lesser offset
66 */
67static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
68 struct rb_node **prev_ret)
69{
70 struct rb_node *n = root->rb_node;
71 struct rb_node *prev = NULL;
72 struct rb_node *test;
73 struct btrfs_ordered_extent *entry;
74 struct btrfs_ordered_extent *prev_entry = NULL;
75
76 while (n) {
77 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
78 prev = n;
79 prev_entry = entry;
80
81 if (file_offset < entry->file_offset)
82 n = n->rb_left;
83 else if (file_offset >= entry_end(entry))
84 n = n->rb_right;
85 else
86 return n;
87 }
88 if (!prev_ret)
89 return NULL;
90
91 while (prev && file_offset >= entry_end(prev_entry)) {
92 test = rb_next(prev);
93 if (!test)
94 break;
95 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
96 rb_node);
97 if (file_offset < entry_end(prev_entry))
98 break;
99
100 prev = test;
101 }
102 if (prev)
103 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
104 rb_node);
105 while (prev && file_offset < entry_end(prev_entry)) {
106 test = rb_prev(prev);
107 if (!test)
108 break;
109 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
110 rb_node);
111 prev = test;
112 }
113 *prev_ret = prev;
114 return NULL;
115}
116
117/*
118 * helper to check if a given offset is inside a given entry
119 */
120static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
121{
122 if (file_offset < entry->file_offset ||
123 entry->file_offset + entry->len <= file_offset)
124 return 0;
125 return 1;
126}
127
128static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
129 u64 len)
130{
131 if (file_offset + len <= entry->file_offset ||
132 entry->file_offset + entry->len <= file_offset)
133 return 0;
134 return 1;
135}
136
137/*
138 * look find the first ordered struct that has this offset, otherwise
139 * the first one less than this offset
140 */
141static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
142 u64 file_offset)
143{
144 struct rb_root *root = &tree->tree;
145 struct rb_node *prev = NULL;
146 struct rb_node *ret;
147 struct btrfs_ordered_extent *entry;
148
149 if (tree->last) {
150 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
151 rb_node);
152 if (offset_in_entry(entry, file_offset))
153 return tree->last;
154 }
155 ret = __tree_search(root, file_offset, &prev);
156 if (!ret)
157 ret = prev;
158 if (ret)
159 tree->last = ret;
160 return ret;
161}
162
163/* allocate and add a new ordered_extent into the per-inode tree.
164 * file_offset is the logical offset in the file
165 *
166 * start is the disk block number of an extent already reserved in the
167 * extent allocation tree
168 *
169 * len is the length of the extent
170 *
171 * The tree is given a single reference on the ordered extent that was
172 * inserted.
173 */
174static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
175 u64 start, u64 len, u64 disk_len,
176 int type, int dio, int compress_type)
177{
178 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
179 struct btrfs_root *root = BTRFS_I(inode)->root;
180 struct btrfs_ordered_inode_tree *tree;
181 struct rb_node *node;
182 struct btrfs_ordered_extent *entry;
183
184 tree = &BTRFS_I(inode)->ordered_tree;
185 entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
186 if (!entry)
187 return -ENOMEM;
188
189 entry->file_offset = file_offset;
190 entry->start = start;
191 entry->len = len;
192 entry->disk_len = disk_len;
193 entry->bytes_left = len;
194 entry->inode = igrab(inode);
195 entry->compress_type = compress_type;
196 entry->truncated_len = (u64)-1;
197 if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
198 set_bit(type, &entry->flags);
199
200 if (dio) {
201 percpu_counter_add_batch(&fs_info->dio_bytes, len,
202 fs_info->delalloc_batch);
203 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
204 }
205
206 /* one ref for the tree */
207 refcount_set(&entry->refs, 1);
208 init_waitqueue_head(&entry->wait);
209 INIT_LIST_HEAD(&entry->list);
210 INIT_LIST_HEAD(&entry->root_extent_list);
211 INIT_LIST_HEAD(&entry->work_list);
212 init_completion(&entry->completion);
213 INIT_LIST_HEAD(&entry->log_list);
214 INIT_LIST_HEAD(&entry->trans_list);
215
216 trace_btrfs_ordered_extent_add(inode, entry);
217
218 spin_lock_irq(&tree->lock);
219 node = tree_insert(&tree->tree, file_offset,
220 &entry->rb_node);
221 if (node)
222 ordered_data_tree_panic(inode, -EEXIST, file_offset);
223 spin_unlock_irq(&tree->lock);
224
225 spin_lock(&root->ordered_extent_lock);
226 list_add_tail(&entry->root_extent_list,
227 &root->ordered_extents);
228 root->nr_ordered_extents++;
229 if (root->nr_ordered_extents == 1) {
230 spin_lock(&fs_info->ordered_root_lock);
231 BUG_ON(!list_empty(&root->ordered_root));
232 list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
233 spin_unlock(&fs_info->ordered_root_lock);
234 }
235 spin_unlock(&root->ordered_extent_lock);
236
237 /*
238 * We don't need the count_max_extents here, we can assume that all of
239 * that work has been done at higher layers, so this is truly the
240 * smallest the extent is going to get.
241 */
242 spin_lock(&BTRFS_I(inode)->lock);
243 btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
244 spin_unlock(&BTRFS_I(inode)->lock);
245
246 return 0;
247}
248
249int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
250 u64 start, u64 len, u64 disk_len, int type)
251{
252 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
253 disk_len, type, 0,
254 BTRFS_COMPRESS_NONE);
255}
256
257int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
258 u64 start, u64 len, u64 disk_len, int type)
259{
260 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
261 disk_len, type, 1,
262 BTRFS_COMPRESS_NONE);
263}
264
265int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
266 u64 start, u64 len, u64 disk_len,
267 int type, int compress_type)
268{
269 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
270 disk_len, type, 0,
271 compress_type);
272}
273
274/*
275 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
276 * when an ordered extent is finished. If the list covers more than one
277 * ordered extent, it is split across multiples.
278 */
279void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
280 struct btrfs_ordered_sum *sum)
281{
282 struct btrfs_ordered_inode_tree *tree;
283
284 tree = &BTRFS_I(entry->inode)->ordered_tree;
285 spin_lock_irq(&tree->lock);
286 list_add_tail(&sum->list, &entry->list);
287 spin_unlock_irq(&tree->lock);
288}
289
290/*
291 * this is used to account for finished IO across a given range
292 * of the file. The IO may span ordered extents. If
293 * a given ordered_extent is completely done, 1 is returned, otherwise
294 * 0.
295 *
296 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
297 * to make sure this function only returns 1 once for a given ordered extent.
298 *
299 * file_offset is updated to one byte past the range that is recorded as
300 * complete. This allows you to walk forward in the file.
301 */
302int btrfs_dec_test_first_ordered_pending(struct inode *inode,
303 struct btrfs_ordered_extent **cached,
304 u64 *file_offset, u64 io_size, int uptodate)
305{
306 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
307 struct btrfs_ordered_inode_tree *tree;
308 struct rb_node *node;
309 struct btrfs_ordered_extent *entry = NULL;
310 int ret;
311 unsigned long flags;
312 u64 dec_end;
313 u64 dec_start;
314 u64 to_dec;
315
316 tree = &BTRFS_I(inode)->ordered_tree;
317 spin_lock_irqsave(&tree->lock, flags);
318 node = tree_search(tree, *file_offset);
319 if (!node) {
320 ret = 1;
321 goto out;
322 }
323
324 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
325 if (!offset_in_entry(entry, *file_offset)) {
326 ret = 1;
327 goto out;
328 }
329
330 dec_start = max(*file_offset, entry->file_offset);
331 dec_end = min(*file_offset + io_size, entry->file_offset +
332 entry->len);
333 *file_offset = dec_end;
334 if (dec_start > dec_end) {
335 btrfs_crit(fs_info, "bad ordering dec_start %llu end %llu",
336 dec_start, dec_end);
337 }
338 to_dec = dec_end - dec_start;
339 if (to_dec > entry->bytes_left) {
340 btrfs_crit(fs_info,
341 "bad ordered accounting left %llu size %llu",
342 entry->bytes_left, to_dec);
343 }
344 entry->bytes_left -= to_dec;
345 if (!uptodate)
346 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
347
348 if (entry->bytes_left == 0) {
349 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
350 /* test_and_set_bit implies a barrier */
351 cond_wake_up_nomb(&entry->wait);
352 } else {
353 ret = 1;
354 }
355out:
356 if (!ret && cached && entry) {
357 *cached = entry;
358 refcount_inc(&entry->refs);
359 }
360 spin_unlock_irqrestore(&tree->lock, flags);
361 return ret == 0;
362}
363
364/*
365 * this is used to account for finished IO across a given range
366 * of the file. The IO should not span ordered extents. If
367 * a given ordered_extent is completely done, 1 is returned, otherwise
368 * 0.
369 *
370 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
371 * to make sure this function only returns 1 once for a given ordered extent.
372 */
373int btrfs_dec_test_ordered_pending(struct inode *inode,
374 struct btrfs_ordered_extent **cached,
375 u64 file_offset, u64 io_size, int uptodate)
376{
377 struct btrfs_ordered_inode_tree *tree;
378 struct rb_node *node;
379 struct btrfs_ordered_extent *entry = NULL;
380 unsigned long flags;
381 int ret;
382
383 tree = &BTRFS_I(inode)->ordered_tree;
384 spin_lock_irqsave(&tree->lock, flags);
385 if (cached && *cached) {
386 entry = *cached;
387 goto have_entry;
388 }
389
390 node = tree_search(tree, file_offset);
391 if (!node) {
392 ret = 1;
393 goto out;
394 }
395
396 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
397have_entry:
398 if (!offset_in_entry(entry, file_offset)) {
399 ret = 1;
400 goto out;
401 }
402
403 if (io_size > entry->bytes_left) {
404 btrfs_crit(BTRFS_I(inode)->root->fs_info,
405 "bad ordered accounting left %llu size %llu",
406 entry->bytes_left, io_size);
407 }
408 entry->bytes_left -= io_size;
409 if (!uptodate)
410 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
411
412 if (entry->bytes_left == 0) {
413 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
414 /* test_and_set_bit implies a barrier */
415 cond_wake_up_nomb(&entry->wait);
416 } else {
417 ret = 1;
418 }
419out:
420 if (!ret && cached && entry) {
421 *cached = entry;
422 refcount_inc(&entry->refs);
423 }
424 spin_unlock_irqrestore(&tree->lock, flags);
425 return ret == 0;
426}
427
428/*
429 * used to drop a reference on an ordered extent. This will free
430 * the extent if the last reference is dropped
431 */
432void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
433{
434 struct list_head *cur;
435 struct btrfs_ordered_sum *sum;
436
437 trace_btrfs_ordered_extent_put(entry->inode, entry);
438
439 if (refcount_dec_and_test(&entry->refs)) {
440 ASSERT(list_empty(&entry->log_list));
441 ASSERT(list_empty(&entry->trans_list));
442 ASSERT(list_empty(&entry->root_extent_list));
443 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
444 if (entry->inode)
445 btrfs_add_delayed_iput(entry->inode);
446 while (!list_empty(&entry->list)) {
447 cur = entry->list.next;
448 sum = list_entry(cur, struct btrfs_ordered_sum, list);
449 list_del(&sum->list);
450 kvfree(sum);
451 }
452 kmem_cache_free(btrfs_ordered_extent_cache, entry);
453 }
454}
455
456/*
457 * remove an ordered extent from the tree. No references are dropped
458 * and waiters are woken up.
459 */
460void btrfs_remove_ordered_extent(struct inode *inode,
461 struct btrfs_ordered_extent *entry)
462{
463 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
464 struct btrfs_ordered_inode_tree *tree;
465 struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
466 struct btrfs_root *root = btrfs_inode->root;
467 struct rb_node *node;
468
469 /* This is paired with btrfs_add_ordered_extent. */
470 spin_lock(&btrfs_inode->lock);
471 btrfs_mod_outstanding_extents(btrfs_inode, -1);
472 spin_unlock(&btrfs_inode->lock);
473 if (root != fs_info->tree_root)
474 btrfs_delalloc_release_metadata(btrfs_inode, entry->len, false);
475
476 if (test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
477 percpu_counter_add_batch(&fs_info->dio_bytes, -entry->len,
478 fs_info->delalloc_batch);
479
480 tree = &btrfs_inode->ordered_tree;
481 spin_lock_irq(&tree->lock);
482 node = &entry->rb_node;
483 rb_erase(node, &tree->tree);
484 RB_CLEAR_NODE(node);
485 if (tree->last == node)
486 tree->last = NULL;
487 set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
488 spin_unlock_irq(&tree->lock);
489
490 spin_lock(&root->ordered_extent_lock);
491 list_del_init(&entry->root_extent_list);
492 root->nr_ordered_extents--;
493
494 trace_btrfs_ordered_extent_remove(inode, entry);
495
496 if (!root->nr_ordered_extents) {
497 spin_lock(&fs_info->ordered_root_lock);
498 BUG_ON(list_empty(&root->ordered_root));
499 list_del_init(&root->ordered_root);
500 spin_unlock(&fs_info->ordered_root_lock);
501 }
502 spin_unlock(&root->ordered_extent_lock);
503 wake_up(&entry->wait);
504}
505
506static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
507{
508 struct btrfs_ordered_extent *ordered;
509
510 ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
511 btrfs_start_ordered_extent(ordered->inode, ordered, 1);
512 complete(&ordered->completion);
513}
514
515/*
516 * wait for all the ordered extents in a root. This is done when balancing
517 * space between drives.
518 */
519u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
520 const u64 range_start, const u64 range_len)
521{
522 struct btrfs_fs_info *fs_info = root->fs_info;
523 LIST_HEAD(splice);
524 LIST_HEAD(skipped);
525 LIST_HEAD(works);
526 struct btrfs_ordered_extent *ordered, *next;
527 u64 count = 0;
528 const u64 range_end = range_start + range_len;
529
530 mutex_lock(&root->ordered_extent_mutex);
531 spin_lock(&root->ordered_extent_lock);
532 list_splice_init(&root->ordered_extents, &splice);
533 while (!list_empty(&splice) && nr) {
534 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
535 root_extent_list);
536
537 if (range_end <= ordered->start ||
538 ordered->start + ordered->disk_len <= range_start) {
539 list_move_tail(&ordered->root_extent_list, &skipped);
540 cond_resched_lock(&root->ordered_extent_lock);
541 continue;
542 }
543
544 list_move_tail(&ordered->root_extent_list,
545 &root->ordered_extents);
546 refcount_inc(&ordered->refs);
547 spin_unlock(&root->ordered_extent_lock);
548
549 btrfs_init_work(&ordered->flush_work,
550 btrfs_flush_delalloc_helper,
551 btrfs_run_ordered_extent_work, NULL, NULL);
552 list_add_tail(&ordered->work_list, &works);
553 btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
554
555 cond_resched();
556 spin_lock(&root->ordered_extent_lock);
557 if (nr != U64_MAX)
558 nr--;
559 count++;
560 }
561 list_splice_tail(&skipped, &root->ordered_extents);
562 list_splice_tail(&splice, &root->ordered_extents);
563 spin_unlock(&root->ordered_extent_lock);
564
565 list_for_each_entry_safe(ordered, next, &works, work_list) {
566 list_del_init(&ordered->work_list);
567 wait_for_completion(&ordered->completion);
568 btrfs_put_ordered_extent(ordered);
569 cond_resched();
570 }
571 mutex_unlock(&root->ordered_extent_mutex);
572
573 return count;
574}
575
576u64 btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
577 const u64 range_start, const u64 range_len)
578{
579 struct btrfs_root *root;
580 struct list_head splice;
581 u64 total_done = 0;
582 u64 done;
583
584 INIT_LIST_HEAD(&splice);
585
586 mutex_lock(&fs_info->ordered_operations_mutex);
587 spin_lock(&fs_info->ordered_root_lock);
588 list_splice_init(&fs_info->ordered_roots, &splice);
589 while (!list_empty(&splice) && nr) {
590 root = list_first_entry(&splice, struct btrfs_root,
591 ordered_root);
592 root = btrfs_grab_fs_root(root);
593 BUG_ON(!root);
594 list_move_tail(&root->ordered_root,
595 &fs_info->ordered_roots);
596 spin_unlock(&fs_info->ordered_root_lock);
597
598 done = btrfs_wait_ordered_extents(root, nr,
599 range_start, range_len);
600 btrfs_put_fs_root(root);
601 total_done += done;
602
603 spin_lock(&fs_info->ordered_root_lock);
604 if (nr != U64_MAX) {
605 nr -= done;
606 }
607 }
608 list_splice_tail(&splice, &fs_info->ordered_roots);
609 spin_unlock(&fs_info->ordered_root_lock);
610 mutex_unlock(&fs_info->ordered_operations_mutex);
611
612 return total_done;
613}
614
615/*
616 * Used to start IO or wait for a given ordered extent to finish.
617 *
618 * If wait is one, this effectively waits on page writeback for all the pages
619 * in the extent, and it waits on the io completion code to insert
620 * metadata into the btree corresponding to the extent
621 */
622void btrfs_start_ordered_extent(struct inode *inode,
623 struct btrfs_ordered_extent *entry,
624 int wait)
625{
626 u64 start = entry->file_offset;
627 u64 end = start + entry->len - 1;
628
629 trace_btrfs_ordered_extent_start(inode, entry);
630
631 /*
632 * pages in the range can be dirty, clean or writeback. We
633 * start IO on any dirty ones so the wait doesn't stall waiting
634 * for the flusher thread to find them
635 */
636 if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
637 filemap_fdatawrite_range(inode->i_mapping, start, end);
638 if (wait) {
639 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
640 &entry->flags));
641 }
642}
643
644/*
645 * Used to wait on ordered extents across a large range of bytes.
646 */
647int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
648{
649 int ret = 0;
650 int ret_wb = 0;
651 u64 end;
652 u64 orig_end;
653 struct btrfs_ordered_extent *ordered;
654
655 if (start + len < start) {
656 orig_end = INT_LIMIT(loff_t);
657 } else {
658 orig_end = start + len - 1;
659 if (orig_end > INT_LIMIT(loff_t))
660 orig_end = INT_LIMIT(loff_t);
661 }
662
663 /* start IO across the range first to instantiate any delalloc
664 * extents
665 */
666 ret = btrfs_fdatawrite_range(inode, start, orig_end);
667 if (ret)
668 return ret;
669
670 /*
671 * If we have a writeback error don't return immediately. Wait first
672 * for any ordered extents that haven't completed yet. This is to make
673 * sure no one can dirty the same page ranges and call writepages()
674 * before the ordered extents complete - to avoid failures (-EEXIST)
675 * when adding the new ordered extents to the ordered tree.
676 */
677 ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
678
679 end = orig_end;
680 while (1) {
681 ordered = btrfs_lookup_first_ordered_extent(inode, end);
682 if (!ordered)
683 break;
684 if (ordered->file_offset > orig_end) {
685 btrfs_put_ordered_extent(ordered);
686 break;
687 }
688 if (ordered->file_offset + ordered->len <= start) {
689 btrfs_put_ordered_extent(ordered);
690 break;
691 }
692 btrfs_start_ordered_extent(inode, ordered, 1);
693 end = ordered->file_offset;
694 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
695 ret = -EIO;
696 btrfs_put_ordered_extent(ordered);
697 if (ret || end == 0 || end == start)
698 break;
699 end--;
700 }
701 return ret_wb ? ret_wb : ret;
702}
703
704/*
705 * find an ordered extent corresponding to file_offset. return NULL if
706 * nothing is found, otherwise take a reference on the extent and return it
707 */
708struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
709 u64 file_offset)
710{
711 struct btrfs_ordered_inode_tree *tree;
712 struct rb_node *node;
713 struct btrfs_ordered_extent *entry = NULL;
714
715 tree = &BTRFS_I(inode)->ordered_tree;
716 spin_lock_irq(&tree->lock);
717 node = tree_search(tree, file_offset);
718 if (!node)
719 goto out;
720
721 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
722 if (!offset_in_entry(entry, file_offset))
723 entry = NULL;
724 if (entry)
725 refcount_inc(&entry->refs);
726out:
727 spin_unlock_irq(&tree->lock);
728 return entry;
729}
730
731/* Since the DIO code tries to lock a wide area we need to look for any ordered
732 * extents that exist in the range, rather than just the start of the range.
733 */
734struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
735 struct btrfs_inode *inode, u64 file_offset, u64 len)
736{
737 struct btrfs_ordered_inode_tree *tree;
738 struct rb_node *node;
739 struct btrfs_ordered_extent *entry = NULL;
740
741 tree = &inode->ordered_tree;
742 spin_lock_irq(&tree->lock);
743 node = tree_search(tree, file_offset);
744 if (!node) {
745 node = tree_search(tree, file_offset + len);
746 if (!node)
747 goto out;
748 }
749
750 while (1) {
751 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
752 if (range_overlaps(entry, file_offset, len))
753 break;
754
755 if (entry->file_offset >= file_offset + len) {
756 entry = NULL;
757 break;
758 }
759 entry = NULL;
760 node = rb_next(node);
761 if (!node)
762 break;
763 }
764out:
765 if (entry)
766 refcount_inc(&entry->refs);
767 spin_unlock_irq(&tree->lock);
768 return entry;
769}
770
771/*
772 * lookup and return any extent before 'file_offset'. NULL is returned
773 * if none is found
774 */
775struct btrfs_ordered_extent *
776btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
777{
778 struct btrfs_ordered_inode_tree *tree;
779 struct rb_node *node;
780 struct btrfs_ordered_extent *entry = NULL;
781
782 tree = &BTRFS_I(inode)->ordered_tree;
783 spin_lock_irq(&tree->lock);
784 node = tree_search(tree, file_offset);
785 if (!node)
786 goto out;
787
788 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
789 refcount_inc(&entry->refs);
790out:
791 spin_unlock_irq(&tree->lock);
792 return entry;
793}
794
795/*
796 * After an extent is done, call this to conditionally update the on disk
797 * i_size. i_size is updated to cover any fully written part of the file.
798 */
799int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
800 struct btrfs_ordered_extent *ordered)
801{
802 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
803 u64 disk_i_size;
804 u64 new_i_size;
805 u64 i_size = i_size_read(inode);
806 struct rb_node *node;
807 struct rb_node *prev = NULL;
808 struct btrfs_ordered_extent *test;
809 int ret = 1;
810 u64 orig_offset = offset;
811
812 spin_lock_irq(&tree->lock);
813 if (ordered) {
814 offset = entry_end(ordered);
815 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
816 offset = min(offset,
817 ordered->file_offset +
818 ordered->truncated_len);
819 } else {
820 offset = ALIGN(offset, btrfs_inode_sectorsize(inode));
821 }
822 disk_i_size = BTRFS_I(inode)->disk_i_size;
823
824 /*
825 * truncate file.
826 * If ordered is not NULL, then this is called from endio and
827 * disk_i_size will be updated by either truncate itself or any
828 * in-flight IOs which are inside the disk_i_size.
829 *
830 * Because btrfs_setsize() may set i_size with disk_i_size if truncate
831 * fails somehow, we need to make sure we have a precise disk_i_size by
832 * updating it as usual.
833 *
834 */
835 if (!ordered && disk_i_size > i_size) {
836 BTRFS_I(inode)->disk_i_size = orig_offset;
837 ret = 0;
838 goto out;
839 }
840
841 /*
842 * if the disk i_size is already at the inode->i_size, or
843 * this ordered extent is inside the disk i_size, we're done
844 */
845 if (disk_i_size == i_size)
846 goto out;
847
848 /*
849 * We still need to update disk_i_size if outstanding_isize is greater
850 * than disk_i_size.
851 */
852 if (offset <= disk_i_size &&
853 (!ordered || ordered->outstanding_isize <= disk_i_size))
854 goto out;
855
856 /*
857 * walk backward from this ordered extent to disk_i_size.
858 * if we find an ordered extent then we can't update disk i_size
859 * yet
860 */
861 if (ordered) {
862 node = rb_prev(&ordered->rb_node);
863 } else {
864 prev = tree_search(tree, offset);
865 /*
866 * we insert file extents without involving ordered struct,
867 * so there should be no ordered struct cover this offset
868 */
869 if (prev) {
870 test = rb_entry(prev, struct btrfs_ordered_extent,
871 rb_node);
872 BUG_ON(offset_in_entry(test, offset));
873 }
874 node = prev;
875 }
876 for (; node; node = rb_prev(node)) {
877 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
878
879 /* We treat this entry as if it doesn't exist */
880 if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
881 continue;
882
883 if (entry_end(test) <= disk_i_size)
884 break;
885 if (test->file_offset >= i_size)
886 break;
887
888 /*
889 * We don't update disk_i_size now, so record this undealt
890 * i_size. Or we will not know the real i_size.
891 */
892 if (test->outstanding_isize < offset)
893 test->outstanding_isize = offset;
894 if (ordered &&
895 ordered->outstanding_isize > test->outstanding_isize)
896 test->outstanding_isize = ordered->outstanding_isize;
897 goto out;
898 }
899 new_i_size = min_t(u64, offset, i_size);
900
901 /*
902 * Some ordered extents may completed before the current one, and
903 * we hold the real i_size in ->outstanding_isize.
904 */
905 if (ordered && ordered->outstanding_isize > new_i_size)
906 new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
907 BTRFS_I(inode)->disk_i_size = new_i_size;
908 ret = 0;
909out:
910 /*
911 * We need to do this because we can't remove ordered extents until
912 * after the i_disk_size has been updated and then the inode has been
913 * updated to reflect the change, so we need to tell anybody who finds
914 * this ordered extent that we've already done all the real work, we
915 * just haven't completed all the other work.
916 */
917 if (ordered)
918 set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
919 spin_unlock_irq(&tree->lock);
920 return ret;
921}
922
923/*
924 * search the ordered extents for one corresponding to 'offset' and
925 * try to find a checksum. This is used because we allow pages to
926 * be reclaimed before their checksum is actually put into the btree
927 */
928int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
929 u8 *sum, int len)
930{
931 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
932 struct btrfs_ordered_sum *ordered_sum;
933 struct btrfs_ordered_extent *ordered;
934 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
935 unsigned long num_sectors;
936 unsigned long i;
937 u32 sectorsize = btrfs_inode_sectorsize(inode);
938 const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
939 int index = 0;
940
941 ordered = btrfs_lookup_ordered_extent(inode, offset);
942 if (!ordered)
943 return 0;
944
945 spin_lock_irq(&tree->lock);
946 list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
947 if (disk_bytenr >= ordered_sum->bytenr &&
948 disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
949 i = (disk_bytenr - ordered_sum->bytenr) >>
950 inode->i_sb->s_blocksize_bits;
951 num_sectors = ordered_sum->len >>
952 inode->i_sb->s_blocksize_bits;
953 num_sectors = min_t(int, len - index, num_sectors - i);
954 memcpy(sum + index, ordered_sum->sums + i * csum_size,
955 num_sectors * csum_size);
956
957 index += (int)num_sectors * csum_size;
958 if (index == len)
959 goto out;
960 disk_bytenr += num_sectors * sectorsize;
961 }
962 }
963out:
964 spin_unlock_irq(&tree->lock);
965 btrfs_put_ordered_extent(ordered);
966 return index;
967}
968
969/*
970 * btrfs_flush_ordered_range - Lock the passed range and ensures all pending
971 * ordered extents in it are run to completion.
972 *
973 * @tree: IO tree used for locking out other users of the range
974 * @inode: Inode whose ordered tree is to be searched
975 * @start: Beginning of range to flush
976 * @end: Last byte of range to lock
977 * @cached_state: If passed, will return the extent state responsible for the
978 * locked range. It's the caller's responsibility to free the cached state.
979 *
980 * This function always returns with the given range locked, ensuring after it's
981 * called no order extent can be pending.
982 */
983void btrfs_lock_and_flush_ordered_range(struct extent_io_tree *tree,
984 struct btrfs_inode *inode, u64 start,
985 u64 end,
986 struct extent_state **cached_state)
987{
988 struct btrfs_ordered_extent *ordered;
989 struct extent_state *cache = NULL;
990 struct extent_state **cachedp = &cache;
991
992 if (cached_state)
993 cachedp = cached_state;
994
995 while (1) {
996 lock_extent_bits(tree, start, end, cachedp);
997 ordered = btrfs_lookup_ordered_range(inode, start,
998 end - start + 1);
999 if (!ordered) {
1000 /*
1001 * If no external cached_state has been passed then
1002 * decrement the extra ref taken for cachedp since we
1003 * aren't exposing it outside of this function
1004 */
1005 if (!cached_state)
1006 refcount_dec(&cache->refs);
1007 break;
1008 }
1009 unlock_extent_cached(tree, start, end, cachedp);
1010 btrfs_start_ordered_extent(&inode->vfs_inode, ordered, 1);
1011 btrfs_put_ordered_extent(ordered);
1012 }
1013}
1014
1015int __init ordered_data_init(void)
1016{
1017 btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1018 sizeof(struct btrfs_ordered_extent), 0,
1019 SLAB_MEM_SPREAD,
1020 NULL);
1021 if (!btrfs_ordered_extent_cache)
1022 return -ENOMEM;
1023
1024 return 0;
1025}
1026
1027void __cold ordered_data_exit(void)
1028{
1029 kmem_cache_destroy(btrfs_ordered_extent_cache);
1030}
1/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/slab.h>
20#include <linux/blkdev.h>
21#include <linux/writeback.h>
22#include <linux/pagevec.h>
23#include "ctree.h"
24#include "transaction.h"
25#include "btrfs_inode.h"
26#include "extent_io.h"
27#include "disk-io.h"
28#include "compression.h"
29
30static struct kmem_cache *btrfs_ordered_extent_cache;
31
32static u64 entry_end(struct btrfs_ordered_extent *entry)
33{
34 if (entry->file_offset + entry->len < entry->file_offset)
35 return (u64)-1;
36 return entry->file_offset + entry->len;
37}
38
39/* returns NULL if the insertion worked, or it returns the node it did find
40 * in the tree
41 */
42static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
43 struct rb_node *node)
44{
45 struct rb_node **p = &root->rb_node;
46 struct rb_node *parent = NULL;
47 struct btrfs_ordered_extent *entry;
48
49 while (*p) {
50 parent = *p;
51 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
52
53 if (file_offset < entry->file_offset)
54 p = &(*p)->rb_left;
55 else if (file_offset >= entry_end(entry))
56 p = &(*p)->rb_right;
57 else
58 return parent;
59 }
60
61 rb_link_node(node, parent, p);
62 rb_insert_color(node, root);
63 return NULL;
64}
65
66static void ordered_data_tree_panic(struct inode *inode, int errno,
67 u64 offset)
68{
69 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
70 btrfs_panic(fs_info, errno, "Inconsistency in ordered tree at offset "
71 "%llu", offset);
72}
73
74/*
75 * look for a given offset in the tree, and if it can't be found return the
76 * first lesser offset
77 */
78static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
79 struct rb_node **prev_ret)
80{
81 struct rb_node *n = root->rb_node;
82 struct rb_node *prev = NULL;
83 struct rb_node *test;
84 struct btrfs_ordered_extent *entry;
85 struct btrfs_ordered_extent *prev_entry = NULL;
86
87 while (n) {
88 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
89 prev = n;
90 prev_entry = entry;
91
92 if (file_offset < entry->file_offset)
93 n = n->rb_left;
94 else if (file_offset >= entry_end(entry))
95 n = n->rb_right;
96 else
97 return n;
98 }
99 if (!prev_ret)
100 return NULL;
101
102 while (prev && file_offset >= entry_end(prev_entry)) {
103 test = rb_next(prev);
104 if (!test)
105 break;
106 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
107 rb_node);
108 if (file_offset < entry_end(prev_entry))
109 break;
110
111 prev = test;
112 }
113 if (prev)
114 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
115 rb_node);
116 while (prev && file_offset < entry_end(prev_entry)) {
117 test = rb_prev(prev);
118 if (!test)
119 break;
120 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
121 rb_node);
122 prev = test;
123 }
124 *prev_ret = prev;
125 return NULL;
126}
127
128/*
129 * helper to check if a given offset is inside a given entry
130 */
131static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
132{
133 if (file_offset < entry->file_offset ||
134 entry->file_offset + entry->len <= file_offset)
135 return 0;
136 return 1;
137}
138
139static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
140 u64 len)
141{
142 if (file_offset + len <= entry->file_offset ||
143 entry->file_offset + entry->len <= file_offset)
144 return 0;
145 return 1;
146}
147
148/*
149 * look find the first ordered struct that has this offset, otherwise
150 * the first one less than this offset
151 */
152static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
153 u64 file_offset)
154{
155 struct rb_root *root = &tree->tree;
156 struct rb_node *prev = NULL;
157 struct rb_node *ret;
158 struct btrfs_ordered_extent *entry;
159
160 if (tree->last) {
161 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
162 rb_node);
163 if (offset_in_entry(entry, file_offset))
164 return tree->last;
165 }
166 ret = __tree_search(root, file_offset, &prev);
167 if (!ret)
168 ret = prev;
169 if (ret)
170 tree->last = ret;
171 return ret;
172}
173
174/* allocate and add a new ordered_extent into the per-inode tree.
175 * file_offset is the logical offset in the file
176 *
177 * start is the disk block number of an extent already reserved in the
178 * extent allocation tree
179 *
180 * len is the length of the extent
181 *
182 * The tree is given a single reference on the ordered extent that was
183 * inserted.
184 */
185static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
186 u64 start, u64 len, u64 disk_len,
187 int type, int dio, int compress_type)
188{
189 struct btrfs_root *root = BTRFS_I(inode)->root;
190 struct btrfs_ordered_inode_tree *tree;
191 struct rb_node *node;
192 struct btrfs_ordered_extent *entry;
193
194 tree = &BTRFS_I(inode)->ordered_tree;
195 entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
196 if (!entry)
197 return -ENOMEM;
198
199 entry->file_offset = file_offset;
200 entry->start = start;
201 entry->len = len;
202 entry->disk_len = disk_len;
203 entry->bytes_left = len;
204 entry->inode = igrab(inode);
205 entry->compress_type = compress_type;
206 entry->truncated_len = (u64)-1;
207 if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
208 set_bit(type, &entry->flags);
209
210 if (dio)
211 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
212
213 /* one ref for the tree */
214 atomic_set(&entry->refs, 1);
215 init_waitqueue_head(&entry->wait);
216 INIT_LIST_HEAD(&entry->list);
217 INIT_LIST_HEAD(&entry->root_extent_list);
218 INIT_LIST_HEAD(&entry->work_list);
219 init_completion(&entry->completion);
220 INIT_LIST_HEAD(&entry->log_list);
221 INIT_LIST_HEAD(&entry->trans_list);
222
223 trace_btrfs_ordered_extent_add(inode, entry);
224
225 spin_lock_irq(&tree->lock);
226 node = tree_insert(&tree->tree, file_offset,
227 &entry->rb_node);
228 if (node)
229 ordered_data_tree_panic(inode, -EEXIST, file_offset);
230 spin_unlock_irq(&tree->lock);
231
232 spin_lock(&root->ordered_extent_lock);
233 list_add_tail(&entry->root_extent_list,
234 &root->ordered_extents);
235 root->nr_ordered_extents++;
236 if (root->nr_ordered_extents == 1) {
237 spin_lock(&root->fs_info->ordered_root_lock);
238 BUG_ON(!list_empty(&root->ordered_root));
239 list_add_tail(&root->ordered_root,
240 &root->fs_info->ordered_roots);
241 spin_unlock(&root->fs_info->ordered_root_lock);
242 }
243 spin_unlock(&root->ordered_extent_lock);
244
245 return 0;
246}
247
248int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
249 u64 start, u64 len, u64 disk_len, int type)
250{
251 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
252 disk_len, type, 0,
253 BTRFS_COMPRESS_NONE);
254}
255
256int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
257 u64 start, u64 len, u64 disk_len, int type)
258{
259 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
260 disk_len, type, 1,
261 BTRFS_COMPRESS_NONE);
262}
263
264int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
265 u64 start, u64 len, u64 disk_len,
266 int type, int compress_type)
267{
268 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
269 disk_len, type, 0,
270 compress_type);
271}
272
273/*
274 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
275 * when an ordered extent is finished. If the list covers more than one
276 * ordered extent, it is split across multiples.
277 */
278void btrfs_add_ordered_sum(struct inode *inode,
279 struct btrfs_ordered_extent *entry,
280 struct btrfs_ordered_sum *sum)
281{
282 struct btrfs_ordered_inode_tree *tree;
283
284 tree = &BTRFS_I(inode)->ordered_tree;
285 spin_lock_irq(&tree->lock);
286 list_add_tail(&sum->list, &entry->list);
287 spin_unlock_irq(&tree->lock);
288}
289
290/*
291 * this is used to account for finished IO across a given range
292 * of the file. The IO may span ordered extents. If
293 * a given ordered_extent is completely done, 1 is returned, otherwise
294 * 0.
295 *
296 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
297 * to make sure this function only returns 1 once for a given ordered extent.
298 *
299 * file_offset is updated to one byte past the range that is recorded as
300 * complete. This allows you to walk forward in the file.
301 */
302int btrfs_dec_test_first_ordered_pending(struct inode *inode,
303 struct btrfs_ordered_extent **cached,
304 u64 *file_offset, u64 io_size, int uptodate)
305{
306 struct btrfs_ordered_inode_tree *tree;
307 struct rb_node *node;
308 struct btrfs_ordered_extent *entry = NULL;
309 int ret;
310 unsigned long flags;
311 u64 dec_end;
312 u64 dec_start;
313 u64 to_dec;
314
315 tree = &BTRFS_I(inode)->ordered_tree;
316 spin_lock_irqsave(&tree->lock, flags);
317 node = tree_search(tree, *file_offset);
318 if (!node) {
319 ret = 1;
320 goto out;
321 }
322
323 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
324 if (!offset_in_entry(entry, *file_offset)) {
325 ret = 1;
326 goto out;
327 }
328
329 dec_start = max(*file_offset, entry->file_offset);
330 dec_end = min(*file_offset + io_size, entry->file_offset +
331 entry->len);
332 *file_offset = dec_end;
333 if (dec_start > dec_end) {
334 btrfs_crit(BTRFS_I(inode)->root->fs_info,
335 "bad ordering dec_start %llu end %llu", dec_start, dec_end);
336 }
337 to_dec = dec_end - dec_start;
338 if (to_dec > entry->bytes_left) {
339 btrfs_crit(BTRFS_I(inode)->root->fs_info,
340 "bad ordered accounting left %llu size %llu",
341 entry->bytes_left, to_dec);
342 }
343 entry->bytes_left -= to_dec;
344 if (!uptodate)
345 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
346
347 if (entry->bytes_left == 0) {
348 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
349 /*
350 * Implicit memory barrier after test_and_set_bit
351 */
352 if (waitqueue_active(&entry->wait))
353 wake_up(&entry->wait);
354 } else {
355 ret = 1;
356 }
357out:
358 if (!ret && cached && entry) {
359 *cached = entry;
360 atomic_inc(&entry->refs);
361 }
362 spin_unlock_irqrestore(&tree->lock, flags);
363 return ret == 0;
364}
365
366/*
367 * this is used to account for finished IO across a given range
368 * of the file. The IO should not span ordered extents. If
369 * a given ordered_extent is completely done, 1 is returned, otherwise
370 * 0.
371 *
372 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
373 * to make sure this function only returns 1 once for a given ordered extent.
374 */
375int btrfs_dec_test_ordered_pending(struct inode *inode,
376 struct btrfs_ordered_extent **cached,
377 u64 file_offset, u64 io_size, int uptodate)
378{
379 struct btrfs_ordered_inode_tree *tree;
380 struct rb_node *node;
381 struct btrfs_ordered_extent *entry = NULL;
382 unsigned long flags;
383 int ret;
384
385 tree = &BTRFS_I(inode)->ordered_tree;
386 spin_lock_irqsave(&tree->lock, flags);
387 if (cached && *cached) {
388 entry = *cached;
389 goto have_entry;
390 }
391
392 node = tree_search(tree, file_offset);
393 if (!node) {
394 ret = 1;
395 goto out;
396 }
397
398 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
399have_entry:
400 if (!offset_in_entry(entry, file_offset)) {
401 ret = 1;
402 goto out;
403 }
404
405 if (io_size > entry->bytes_left) {
406 btrfs_crit(BTRFS_I(inode)->root->fs_info,
407 "bad ordered accounting left %llu size %llu",
408 entry->bytes_left, io_size);
409 }
410 entry->bytes_left -= io_size;
411 if (!uptodate)
412 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
413
414 if (entry->bytes_left == 0) {
415 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
416 /*
417 * Implicit memory barrier after test_and_set_bit
418 */
419 if (waitqueue_active(&entry->wait))
420 wake_up(&entry->wait);
421 } else {
422 ret = 1;
423 }
424out:
425 if (!ret && cached && entry) {
426 *cached = entry;
427 atomic_inc(&entry->refs);
428 }
429 spin_unlock_irqrestore(&tree->lock, flags);
430 return ret == 0;
431}
432
433/* Needs to either be called under a log transaction or the log_mutex */
434void btrfs_get_logged_extents(struct inode *inode,
435 struct list_head *logged_list,
436 const loff_t start,
437 const loff_t end)
438{
439 struct btrfs_ordered_inode_tree *tree;
440 struct btrfs_ordered_extent *ordered;
441 struct rb_node *n;
442 struct rb_node *prev;
443
444 tree = &BTRFS_I(inode)->ordered_tree;
445 spin_lock_irq(&tree->lock);
446 n = __tree_search(&tree->tree, end, &prev);
447 if (!n)
448 n = prev;
449 for (; n; n = rb_prev(n)) {
450 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
451 if (ordered->file_offset > end)
452 continue;
453 if (entry_end(ordered) <= start)
454 break;
455 if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
456 continue;
457 list_add(&ordered->log_list, logged_list);
458 atomic_inc(&ordered->refs);
459 }
460 spin_unlock_irq(&tree->lock);
461}
462
463void btrfs_put_logged_extents(struct list_head *logged_list)
464{
465 struct btrfs_ordered_extent *ordered;
466
467 while (!list_empty(logged_list)) {
468 ordered = list_first_entry(logged_list,
469 struct btrfs_ordered_extent,
470 log_list);
471 list_del_init(&ordered->log_list);
472 btrfs_put_ordered_extent(ordered);
473 }
474}
475
476void btrfs_submit_logged_extents(struct list_head *logged_list,
477 struct btrfs_root *log)
478{
479 int index = log->log_transid % 2;
480
481 spin_lock_irq(&log->log_extents_lock[index]);
482 list_splice_tail(logged_list, &log->logged_list[index]);
483 spin_unlock_irq(&log->log_extents_lock[index]);
484}
485
486void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans,
487 struct btrfs_root *log, u64 transid)
488{
489 struct btrfs_ordered_extent *ordered;
490 int index = transid % 2;
491
492 spin_lock_irq(&log->log_extents_lock[index]);
493 while (!list_empty(&log->logged_list[index])) {
494 struct inode *inode;
495 ordered = list_first_entry(&log->logged_list[index],
496 struct btrfs_ordered_extent,
497 log_list);
498 list_del_init(&ordered->log_list);
499 inode = ordered->inode;
500 spin_unlock_irq(&log->log_extents_lock[index]);
501
502 if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) &&
503 !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
504 u64 start = ordered->file_offset;
505 u64 end = ordered->file_offset + ordered->len - 1;
506
507 WARN_ON(!inode);
508 filemap_fdatawrite_range(inode->i_mapping, start, end);
509 }
510 wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE,
511 &ordered->flags));
512
513 /*
514 * In order to keep us from losing our ordered extent
515 * information when committing the transaction we have to make
516 * sure that any logged extents are completed when we go to
517 * commit the transaction. To do this we simply increase the
518 * current transactions pending_ordered counter and decrement it
519 * when the ordered extent completes.
520 */
521 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
522 struct btrfs_ordered_inode_tree *tree;
523
524 tree = &BTRFS_I(inode)->ordered_tree;
525 spin_lock_irq(&tree->lock);
526 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
527 set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
528 atomic_inc(&trans->transaction->pending_ordered);
529 }
530 spin_unlock_irq(&tree->lock);
531 }
532 btrfs_put_ordered_extent(ordered);
533 spin_lock_irq(&log->log_extents_lock[index]);
534 }
535 spin_unlock_irq(&log->log_extents_lock[index]);
536}
537
538void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid)
539{
540 struct btrfs_ordered_extent *ordered;
541 int index = transid % 2;
542
543 spin_lock_irq(&log->log_extents_lock[index]);
544 while (!list_empty(&log->logged_list[index])) {
545 ordered = list_first_entry(&log->logged_list[index],
546 struct btrfs_ordered_extent,
547 log_list);
548 list_del_init(&ordered->log_list);
549 spin_unlock_irq(&log->log_extents_lock[index]);
550 btrfs_put_ordered_extent(ordered);
551 spin_lock_irq(&log->log_extents_lock[index]);
552 }
553 spin_unlock_irq(&log->log_extents_lock[index]);
554}
555
556/*
557 * used to drop a reference on an ordered extent. This will free
558 * the extent if the last reference is dropped
559 */
560void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
561{
562 struct list_head *cur;
563 struct btrfs_ordered_sum *sum;
564
565 trace_btrfs_ordered_extent_put(entry->inode, entry);
566
567 if (atomic_dec_and_test(&entry->refs)) {
568 ASSERT(list_empty(&entry->log_list));
569 ASSERT(list_empty(&entry->trans_list));
570 ASSERT(list_empty(&entry->root_extent_list));
571 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
572 if (entry->inode)
573 btrfs_add_delayed_iput(entry->inode);
574 while (!list_empty(&entry->list)) {
575 cur = entry->list.next;
576 sum = list_entry(cur, struct btrfs_ordered_sum, list);
577 list_del(&sum->list);
578 kfree(sum);
579 }
580 kmem_cache_free(btrfs_ordered_extent_cache, entry);
581 }
582}
583
584/*
585 * remove an ordered extent from the tree. No references are dropped
586 * and waiters are woken up.
587 */
588void btrfs_remove_ordered_extent(struct inode *inode,
589 struct btrfs_ordered_extent *entry)
590{
591 struct btrfs_ordered_inode_tree *tree;
592 struct btrfs_root *root = BTRFS_I(inode)->root;
593 struct rb_node *node;
594 bool dec_pending_ordered = false;
595
596 tree = &BTRFS_I(inode)->ordered_tree;
597 spin_lock_irq(&tree->lock);
598 node = &entry->rb_node;
599 rb_erase(node, &tree->tree);
600 RB_CLEAR_NODE(node);
601 if (tree->last == node)
602 tree->last = NULL;
603 set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
604 if (test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags))
605 dec_pending_ordered = true;
606 spin_unlock_irq(&tree->lock);
607
608 /*
609 * The current running transaction is waiting on us, we need to let it
610 * know that we're complete and wake it up.
611 */
612 if (dec_pending_ordered) {
613 struct btrfs_transaction *trans;
614
615 /*
616 * The checks for trans are just a formality, it should be set,
617 * but if it isn't we don't want to deref/assert under the spin
618 * lock, so be nice and check if trans is set, but ASSERT() so
619 * if it isn't set a developer will notice.
620 */
621 spin_lock(&root->fs_info->trans_lock);
622 trans = root->fs_info->running_transaction;
623 if (trans)
624 atomic_inc(&trans->use_count);
625 spin_unlock(&root->fs_info->trans_lock);
626
627 ASSERT(trans);
628 if (trans) {
629 if (atomic_dec_and_test(&trans->pending_ordered))
630 wake_up(&trans->pending_wait);
631 btrfs_put_transaction(trans);
632 }
633 }
634
635 spin_lock(&root->ordered_extent_lock);
636 list_del_init(&entry->root_extent_list);
637 root->nr_ordered_extents--;
638
639 trace_btrfs_ordered_extent_remove(inode, entry);
640
641 if (!root->nr_ordered_extents) {
642 spin_lock(&root->fs_info->ordered_root_lock);
643 BUG_ON(list_empty(&root->ordered_root));
644 list_del_init(&root->ordered_root);
645 spin_unlock(&root->fs_info->ordered_root_lock);
646 }
647 spin_unlock(&root->ordered_extent_lock);
648 wake_up(&entry->wait);
649}
650
651static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
652{
653 struct btrfs_ordered_extent *ordered;
654
655 ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
656 btrfs_start_ordered_extent(ordered->inode, ordered, 1);
657 complete(&ordered->completion);
658}
659
660/*
661 * wait for all the ordered extents in a root. This is done when balancing
662 * space between drives.
663 */
664int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr)
665{
666 struct list_head splice, works;
667 struct btrfs_ordered_extent *ordered, *next;
668 int count = 0;
669
670 INIT_LIST_HEAD(&splice);
671 INIT_LIST_HEAD(&works);
672
673 mutex_lock(&root->ordered_extent_mutex);
674 spin_lock(&root->ordered_extent_lock);
675 list_splice_init(&root->ordered_extents, &splice);
676 while (!list_empty(&splice) && nr) {
677 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
678 root_extent_list);
679 list_move_tail(&ordered->root_extent_list,
680 &root->ordered_extents);
681 atomic_inc(&ordered->refs);
682 spin_unlock(&root->ordered_extent_lock);
683
684 btrfs_init_work(&ordered->flush_work,
685 btrfs_flush_delalloc_helper,
686 btrfs_run_ordered_extent_work, NULL, NULL);
687 list_add_tail(&ordered->work_list, &works);
688 btrfs_queue_work(root->fs_info->flush_workers,
689 &ordered->flush_work);
690
691 cond_resched();
692 spin_lock(&root->ordered_extent_lock);
693 if (nr != -1)
694 nr--;
695 count++;
696 }
697 list_splice_tail(&splice, &root->ordered_extents);
698 spin_unlock(&root->ordered_extent_lock);
699
700 list_for_each_entry_safe(ordered, next, &works, work_list) {
701 list_del_init(&ordered->work_list);
702 wait_for_completion(&ordered->completion);
703 btrfs_put_ordered_extent(ordered);
704 cond_resched();
705 }
706 mutex_unlock(&root->ordered_extent_mutex);
707
708 return count;
709}
710
711void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr)
712{
713 struct btrfs_root *root;
714 struct list_head splice;
715 int done;
716
717 INIT_LIST_HEAD(&splice);
718
719 mutex_lock(&fs_info->ordered_operations_mutex);
720 spin_lock(&fs_info->ordered_root_lock);
721 list_splice_init(&fs_info->ordered_roots, &splice);
722 while (!list_empty(&splice) && nr) {
723 root = list_first_entry(&splice, struct btrfs_root,
724 ordered_root);
725 root = btrfs_grab_fs_root(root);
726 BUG_ON(!root);
727 list_move_tail(&root->ordered_root,
728 &fs_info->ordered_roots);
729 spin_unlock(&fs_info->ordered_root_lock);
730
731 done = btrfs_wait_ordered_extents(root, nr);
732 btrfs_put_fs_root(root);
733
734 spin_lock(&fs_info->ordered_root_lock);
735 if (nr != -1) {
736 nr -= done;
737 WARN_ON(nr < 0);
738 }
739 }
740 list_splice_tail(&splice, &fs_info->ordered_roots);
741 spin_unlock(&fs_info->ordered_root_lock);
742 mutex_unlock(&fs_info->ordered_operations_mutex);
743}
744
745/*
746 * Used to start IO or wait for a given ordered extent to finish.
747 *
748 * If wait is one, this effectively waits on page writeback for all the pages
749 * in the extent, and it waits on the io completion code to insert
750 * metadata into the btree corresponding to the extent
751 */
752void btrfs_start_ordered_extent(struct inode *inode,
753 struct btrfs_ordered_extent *entry,
754 int wait)
755{
756 u64 start = entry->file_offset;
757 u64 end = start + entry->len - 1;
758
759 trace_btrfs_ordered_extent_start(inode, entry);
760
761 /*
762 * pages in the range can be dirty, clean or writeback. We
763 * start IO on any dirty ones so the wait doesn't stall waiting
764 * for the flusher thread to find them
765 */
766 if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
767 filemap_fdatawrite_range(inode->i_mapping, start, end);
768 if (wait) {
769 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
770 &entry->flags));
771 }
772}
773
774/*
775 * Used to wait on ordered extents across a large range of bytes.
776 */
777int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
778{
779 int ret = 0;
780 int ret_wb = 0;
781 u64 end;
782 u64 orig_end;
783 struct btrfs_ordered_extent *ordered;
784
785 if (start + len < start) {
786 orig_end = INT_LIMIT(loff_t);
787 } else {
788 orig_end = start + len - 1;
789 if (orig_end > INT_LIMIT(loff_t))
790 orig_end = INT_LIMIT(loff_t);
791 }
792
793 /* start IO across the range first to instantiate any delalloc
794 * extents
795 */
796 ret = btrfs_fdatawrite_range(inode, start, orig_end);
797 if (ret)
798 return ret;
799
800 /*
801 * If we have a writeback error don't return immediately. Wait first
802 * for any ordered extents that haven't completed yet. This is to make
803 * sure no one can dirty the same page ranges and call writepages()
804 * before the ordered extents complete - to avoid failures (-EEXIST)
805 * when adding the new ordered extents to the ordered tree.
806 */
807 ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
808
809 end = orig_end;
810 while (1) {
811 ordered = btrfs_lookup_first_ordered_extent(inode, end);
812 if (!ordered)
813 break;
814 if (ordered->file_offset > orig_end) {
815 btrfs_put_ordered_extent(ordered);
816 break;
817 }
818 if (ordered->file_offset + ordered->len <= start) {
819 btrfs_put_ordered_extent(ordered);
820 break;
821 }
822 btrfs_start_ordered_extent(inode, ordered, 1);
823 end = ordered->file_offset;
824 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
825 ret = -EIO;
826 btrfs_put_ordered_extent(ordered);
827 if (ret || end == 0 || end == start)
828 break;
829 end--;
830 }
831 return ret_wb ? ret_wb : ret;
832}
833
834/*
835 * find an ordered extent corresponding to file_offset. return NULL if
836 * nothing is found, otherwise take a reference on the extent and return it
837 */
838struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
839 u64 file_offset)
840{
841 struct btrfs_ordered_inode_tree *tree;
842 struct rb_node *node;
843 struct btrfs_ordered_extent *entry = NULL;
844
845 tree = &BTRFS_I(inode)->ordered_tree;
846 spin_lock_irq(&tree->lock);
847 node = tree_search(tree, file_offset);
848 if (!node)
849 goto out;
850
851 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
852 if (!offset_in_entry(entry, file_offset))
853 entry = NULL;
854 if (entry)
855 atomic_inc(&entry->refs);
856out:
857 spin_unlock_irq(&tree->lock);
858 return entry;
859}
860
861/* Since the DIO code tries to lock a wide area we need to look for any ordered
862 * extents that exist in the range, rather than just the start of the range.
863 */
864struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
865 u64 file_offset,
866 u64 len)
867{
868 struct btrfs_ordered_inode_tree *tree;
869 struct rb_node *node;
870 struct btrfs_ordered_extent *entry = NULL;
871
872 tree = &BTRFS_I(inode)->ordered_tree;
873 spin_lock_irq(&tree->lock);
874 node = tree_search(tree, file_offset);
875 if (!node) {
876 node = tree_search(tree, file_offset + len);
877 if (!node)
878 goto out;
879 }
880
881 while (1) {
882 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
883 if (range_overlaps(entry, file_offset, len))
884 break;
885
886 if (entry->file_offset >= file_offset + len) {
887 entry = NULL;
888 break;
889 }
890 entry = NULL;
891 node = rb_next(node);
892 if (!node)
893 break;
894 }
895out:
896 if (entry)
897 atomic_inc(&entry->refs);
898 spin_unlock_irq(&tree->lock);
899 return entry;
900}
901
902bool btrfs_have_ordered_extents_in_range(struct inode *inode,
903 u64 file_offset,
904 u64 len)
905{
906 struct btrfs_ordered_extent *oe;
907
908 oe = btrfs_lookup_ordered_range(inode, file_offset, len);
909 if (oe) {
910 btrfs_put_ordered_extent(oe);
911 return true;
912 }
913 return false;
914}
915
916/*
917 * lookup and return any extent before 'file_offset'. NULL is returned
918 * if none is found
919 */
920struct btrfs_ordered_extent *
921btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
922{
923 struct btrfs_ordered_inode_tree *tree;
924 struct rb_node *node;
925 struct btrfs_ordered_extent *entry = NULL;
926
927 tree = &BTRFS_I(inode)->ordered_tree;
928 spin_lock_irq(&tree->lock);
929 node = tree_search(tree, file_offset);
930 if (!node)
931 goto out;
932
933 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
934 atomic_inc(&entry->refs);
935out:
936 spin_unlock_irq(&tree->lock);
937 return entry;
938}
939
940/*
941 * After an extent is done, call this to conditionally update the on disk
942 * i_size. i_size is updated to cover any fully written part of the file.
943 */
944int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
945 struct btrfs_ordered_extent *ordered)
946{
947 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
948 u64 disk_i_size;
949 u64 new_i_size;
950 u64 i_size = i_size_read(inode);
951 struct rb_node *node;
952 struct rb_node *prev = NULL;
953 struct btrfs_ordered_extent *test;
954 int ret = 1;
955
956 spin_lock_irq(&tree->lock);
957 if (ordered) {
958 offset = entry_end(ordered);
959 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
960 offset = min(offset,
961 ordered->file_offset +
962 ordered->truncated_len);
963 } else {
964 offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize);
965 }
966 disk_i_size = BTRFS_I(inode)->disk_i_size;
967
968 /* truncate file */
969 if (disk_i_size > i_size) {
970 BTRFS_I(inode)->disk_i_size = i_size;
971 ret = 0;
972 goto out;
973 }
974
975 /*
976 * if the disk i_size is already at the inode->i_size, or
977 * this ordered extent is inside the disk i_size, we're done
978 */
979 if (disk_i_size == i_size)
980 goto out;
981
982 /*
983 * We still need to update disk_i_size if outstanding_isize is greater
984 * than disk_i_size.
985 */
986 if (offset <= disk_i_size &&
987 (!ordered || ordered->outstanding_isize <= disk_i_size))
988 goto out;
989
990 /*
991 * walk backward from this ordered extent to disk_i_size.
992 * if we find an ordered extent then we can't update disk i_size
993 * yet
994 */
995 if (ordered) {
996 node = rb_prev(&ordered->rb_node);
997 } else {
998 prev = tree_search(tree, offset);
999 /*
1000 * we insert file extents without involving ordered struct,
1001 * so there should be no ordered struct cover this offset
1002 */
1003 if (prev) {
1004 test = rb_entry(prev, struct btrfs_ordered_extent,
1005 rb_node);
1006 BUG_ON(offset_in_entry(test, offset));
1007 }
1008 node = prev;
1009 }
1010 for (; node; node = rb_prev(node)) {
1011 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
1012
1013 /* We treat this entry as if it doesn't exist */
1014 if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
1015 continue;
1016 if (test->file_offset + test->len <= disk_i_size)
1017 break;
1018 if (test->file_offset >= i_size)
1019 break;
1020 if (entry_end(test) > disk_i_size) {
1021 /*
1022 * we don't update disk_i_size now, so record this
1023 * undealt i_size. Or we will not know the real
1024 * i_size.
1025 */
1026 if (test->outstanding_isize < offset)
1027 test->outstanding_isize = offset;
1028 if (ordered &&
1029 ordered->outstanding_isize >
1030 test->outstanding_isize)
1031 test->outstanding_isize =
1032 ordered->outstanding_isize;
1033 goto out;
1034 }
1035 }
1036 new_i_size = min_t(u64, offset, i_size);
1037
1038 /*
1039 * Some ordered extents may completed before the current one, and
1040 * we hold the real i_size in ->outstanding_isize.
1041 */
1042 if (ordered && ordered->outstanding_isize > new_i_size)
1043 new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
1044 BTRFS_I(inode)->disk_i_size = new_i_size;
1045 ret = 0;
1046out:
1047 /*
1048 * We need to do this because we can't remove ordered extents until
1049 * after the i_disk_size has been updated and then the inode has been
1050 * updated to reflect the change, so we need to tell anybody who finds
1051 * this ordered extent that we've already done all the real work, we
1052 * just haven't completed all the other work.
1053 */
1054 if (ordered)
1055 set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
1056 spin_unlock_irq(&tree->lock);
1057 return ret;
1058}
1059
1060/*
1061 * search the ordered extents for one corresponding to 'offset' and
1062 * try to find a checksum. This is used because we allow pages to
1063 * be reclaimed before their checksum is actually put into the btree
1064 */
1065int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
1066 u32 *sum, int len)
1067{
1068 struct btrfs_ordered_sum *ordered_sum;
1069 struct btrfs_ordered_extent *ordered;
1070 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
1071 unsigned long num_sectors;
1072 unsigned long i;
1073 u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
1074 int index = 0;
1075
1076 ordered = btrfs_lookup_ordered_extent(inode, offset);
1077 if (!ordered)
1078 return 0;
1079
1080 spin_lock_irq(&tree->lock);
1081 list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
1082 if (disk_bytenr >= ordered_sum->bytenr &&
1083 disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
1084 i = (disk_bytenr - ordered_sum->bytenr) >>
1085 inode->i_sb->s_blocksize_bits;
1086 num_sectors = ordered_sum->len >>
1087 inode->i_sb->s_blocksize_bits;
1088 num_sectors = min_t(int, len - index, num_sectors - i);
1089 memcpy(sum + index, ordered_sum->sums + i,
1090 num_sectors);
1091
1092 index += (int)num_sectors;
1093 if (index == len)
1094 goto out;
1095 disk_bytenr += num_sectors * sectorsize;
1096 }
1097 }
1098out:
1099 spin_unlock_irq(&tree->lock);
1100 btrfs_put_ordered_extent(ordered);
1101 return index;
1102}
1103
1104int __init ordered_data_init(void)
1105{
1106 btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1107 sizeof(struct btrfs_ordered_extent), 0,
1108 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
1109 NULL);
1110 if (!btrfs_ordered_extent_cache)
1111 return -ENOMEM;
1112
1113 return 0;
1114}
1115
1116void ordered_data_exit(void)
1117{
1118 kmem_cache_destroy(btrfs_ordered_extent_cache);
1119}