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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
28static u64 entry_end(struct btrfs_ordered_extent *entry)
29{
30 if (entry->file_offset + entry->len < entry->file_offset)
31 return (u64)-1;
32 return entry->file_offset + entry->len;
33}
34
35/* returns NULL if the insertion worked, or it returns the node it did find
36 * in the tree
37 */
38static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
39 struct rb_node *node)
40{
41 struct rb_node **p = &root->rb_node;
42 struct rb_node *parent = NULL;
43 struct btrfs_ordered_extent *entry;
44
45 while (*p) {
46 parent = *p;
47 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
48
49 if (file_offset < entry->file_offset)
50 p = &(*p)->rb_left;
51 else if (file_offset >= entry_end(entry))
52 p = &(*p)->rb_right;
53 else
54 return parent;
55 }
56
57 rb_link_node(node, parent, p);
58 rb_insert_color(node, root);
59 return NULL;
60}
61
62/*
63 * look for a given offset in the tree, and if it can't be found return the
64 * first lesser offset
65 */
66static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
67 struct rb_node **prev_ret)
68{
69 struct rb_node *n = root->rb_node;
70 struct rb_node *prev = NULL;
71 struct rb_node *test;
72 struct btrfs_ordered_extent *entry;
73 struct btrfs_ordered_extent *prev_entry = NULL;
74
75 while (n) {
76 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
77 prev = n;
78 prev_entry = entry;
79
80 if (file_offset < entry->file_offset)
81 n = n->rb_left;
82 else if (file_offset >= entry_end(entry))
83 n = n->rb_right;
84 else
85 return n;
86 }
87 if (!prev_ret)
88 return NULL;
89
90 while (prev && file_offset >= entry_end(prev_entry)) {
91 test = rb_next(prev);
92 if (!test)
93 break;
94 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
95 rb_node);
96 if (file_offset < entry_end(prev_entry))
97 break;
98
99 prev = test;
100 }
101 if (prev)
102 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
103 rb_node);
104 while (prev && file_offset < entry_end(prev_entry)) {
105 test = rb_prev(prev);
106 if (!test)
107 break;
108 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
109 rb_node);
110 prev = test;
111 }
112 *prev_ret = prev;
113 return NULL;
114}
115
116/*
117 * helper to check if a given offset is inside a given entry
118 */
119static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
120{
121 if (file_offset < entry->file_offset ||
122 entry->file_offset + entry->len <= file_offset)
123 return 0;
124 return 1;
125}
126
127static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
128 u64 len)
129{
130 if (file_offset + len <= entry->file_offset ||
131 entry->file_offset + entry->len <= file_offset)
132 return 0;
133 return 1;
134}
135
136/*
137 * look find the first ordered struct that has this offset, otherwise
138 * the first one less than this offset
139 */
140static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
141 u64 file_offset)
142{
143 struct rb_root *root = &tree->tree;
144 struct rb_node *prev = NULL;
145 struct rb_node *ret;
146 struct btrfs_ordered_extent *entry;
147
148 if (tree->last) {
149 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
150 rb_node);
151 if (offset_in_entry(entry, file_offset))
152 return tree->last;
153 }
154 ret = __tree_search(root, file_offset, &prev);
155 if (!ret)
156 ret = prev;
157 if (ret)
158 tree->last = ret;
159 return ret;
160}
161
162/* allocate and add a new ordered_extent into the per-inode tree.
163 * file_offset is the logical offset in the file
164 *
165 * start is the disk block number of an extent already reserved in the
166 * extent allocation tree
167 *
168 * len is the length of the extent
169 *
170 * The tree is given a single reference on the ordered extent that was
171 * inserted.
172 */
173static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
174 u64 start, u64 len, u64 disk_len,
175 int type, int dio, int compress_type)
176{
177 struct btrfs_ordered_inode_tree *tree;
178 struct rb_node *node;
179 struct btrfs_ordered_extent *entry;
180
181 tree = &BTRFS_I(inode)->ordered_tree;
182 entry = kzalloc(sizeof(*entry), GFP_NOFS);
183 if (!entry)
184 return -ENOMEM;
185
186 entry->file_offset = file_offset;
187 entry->start = start;
188 entry->len = len;
189 entry->disk_len = disk_len;
190 entry->bytes_left = len;
191 entry->inode = inode;
192 entry->compress_type = compress_type;
193 if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
194 set_bit(type, &entry->flags);
195
196 if (dio)
197 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
198
199 /* one ref for the tree */
200 atomic_set(&entry->refs, 1);
201 init_waitqueue_head(&entry->wait);
202 INIT_LIST_HEAD(&entry->list);
203 INIT_LIST_HEAD(&entry->root_extent_list);
204
205 trace_btrfs_ordered_extent_add(inode, entry);
206
207 spin_lock(&tree->lock);
208 node = tree_insert(&tree->tree, file_offset,
209 &entry->rb_node);
210 BUG_ON(node);
211 spin_unlock(&tree->lock);
212
213 spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
214 list_add_tail(&entry->root_extent_list,
215 &BTRFS_I(inode)->root->fs_info->ordered_extents);
216 spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
217
218 BUG_ON(node);
219 return 0;
220}
221
222int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
223 u64 start, u64 len, u64 disk_len, int type)
224{
225 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
226 disk_len, type, 0,
227 BTRFS_COMPRESS_NONE);
228}
229
230int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
231 u64 start, u64 len, u64 disk_len, int type)
232{
233 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
234 disk_len, type, 1,
235 BTRFS_COMPRESS_NONE);
236}
237
238int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
239 u64 start, u64 len, u64 disk_len,
240 int type, int compress_type)
241{
242 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
243 disk_len, type, 0,
244 compress_type);
245}
246
247/*
248 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
249 * when an ordered extent is finished. If the list covers more than one
250 * ordered extent, it is split across multiples.
251 */
252int btrfs_add_ordered_sum(struct inode *inode,
253 struct btrfs_ordered_extent *entry,
254 struct btrfs_ordered_sum *sum)
255{
256 struct btrfs_ordered_inode_tree *tree;
257
258 tree = &BTRFS_I(inode)->ordered_tree;
259 spin_lock(&tree->lock);
260 list_add_tail(&sum->list, &entry->list);
261 spin_unlock(&tree->lock);
262 return 0;
263}
264
265/*
266 * this is used to account for finished IO across a given range
267 * of the file. The IO may span ordered extents. If
268 * a given ordered_extent is completely done, 1 is returned, otherwise
269 * 0.
270 *
271 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
272 * to make sure this function only returns 1 once for a given ordered extent.
273 *
274 * file_offset is updated to one byte past the range that is recorded as
275 * complete. This allows you to walk forward in the file.
276 */
277int btrfs_dec_test_first_ordered_pending(struct inode *inode,
278 struct btrfs_ordered_extent **cached,
279 u64 *file_offset, u64 io_size)
280{
281 struct btrfs_ordered_inode_tree *tree;
282 struct rb_node *node;
283 struct btrfs_ordered_extent *entry = NULL;
284 int ret;
285 u64 dec_end;
286 u64 dec_start;
287 u64 to_dec;
288
289 tree = &BTRFS_I(inode)->ordered_tree;
290 spin_lock(&tree->lock);
291 node = tree_search(tree, *file_offset);
292 if (!node) {
293 ret = 1;
294 goto out;
295 }
296
297 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
298 if (!offset_in_entry(entry, *file_offset)) {
299 ret = 1;
300 goto out;
301 }
302
303 dec_start = max(*file_offset, entry->file_offset);
304 dec_end = min(*file_offset + io_size, entry->file_offset +
305 entry->len);
306 *file_offset = dec_end;
307 if (dec_start > dec_end) {
308 printk(KERN_CRIT "bad ordering dec_start %llu end %llu\n",
309 (unsigned long long)dec_start,
310 (unsigned long long)dec_end);
311 }
312 to_dec = dec_end - dec_start;
313 if (to_dec > entry->bytes_left) {
314 printk(KERN_CRIT "bad ordered accounting left %llu size %llu\n",
315 (unsigned long long)entry->bytes_left,
316 (unsigned long long)to_dec);
317 }
318 entry->bytes_left -= to_dec;
319 if (entry->bytes_left == 0)
320 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
321 else
322 ret = 1;
323out:
324 if (!ret && cached && entry) {
325 *cached = entry;
326 atomic_inc(&entry->refs);
327 }
328 spin_unlock(&tree->lock);
329 return ret == 0;
330}
331
332/*
333 * this is used to account for finished IO across a given range
334 * of the file. The IO should not span ordered extents. If
335 * a given ordered_extent is completely done, 1 is returned, otherwise
336 * 0.
337 *
338 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
339 * to make sure this function only returns 1 once for a given ordered extent.
340 */
341int btrfs_dec_test_ordered_pending(struct inode *inode,
342 struct btrfs_ordered_extent **cached,
343 u64 file_offset, u64 io_size)
344{
345 struct btrfs_ordered_inode_tree *tree;
346 struct rb_node *node;
347 struct btrfs_ordered_extent *entry = NULL;
348 int ret;
349
350 tree = &BTRFS_I(inode)->ordered_tree;
351 spin_lock(&tree->lock);
352 node = tree_search(tree, file_offset);
353 if (!node) {
354 ret = 1;
355 goto out;
356 }
357
358 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
359 if (!offset_in_entry(entry, file_offset)) {
360 ret = 1;
361 goto out;
362 }
363
364 if (io_size > entry->bytes_left) {
365 printk(KERN_CRIT "bad ordered accounting left %llu size %llu\n",
366 (unsigned long long)entry->bytes_left,
367 (unsigned long long)io_size);
368 }
369 entry->bytes_left -= io_size;
370 if (entry->bytes_left == 0)
371 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
372 else
373 ret = 1;
374out:
375 if (!ret && cached && entry) {
376 *cached = entry;
377 atomic_inc(&entry->refs);
378 }
379 spin_unlock(&tree->lock);
380 return ret == 0;
381}
382
383/*
384 * used to drop a reference on an ordered extent. This will free
385 * the extent if the last reference is dropped
386 */
387int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
388{
389 struct list_head *cur;
390 struct btrfs_ordered_sum *sum;
391
392 trace_btrfs_ordered_extent_put(entry->inode, entry);
393
394 if (atomic_dec_and_test(&entry->refs)) {
395 while (!list_empty(&entry->list)) {
396 cur = entry->list.next;
397 sum = list_entry(cur, struct btrfs_ordered_sum, list);
398 list_del(&sum->list);
399 kfree(sum);
400 }
401 kfree(entry);
402 }
403 return 0;
404}
405
406/*
407 * remove an ordered extent from the tree. No references are dropped
408 * and you must wake_up entry->wait. You must hold the tree lock
409 * while you call this function.
410 */
411static int __btrfs_remove_ordered_extent(struct inode *inode,
412 struct btrfs_ordered_extent *entry)
413{
414 struct btrfs_ordered_inode_tree *tree;
415 struct btrfs_root *root = BTRFS_I(inode)->root;
416 struct rb_node *node;
417
418 tree = &BTRFS_I(inode)->ordered_tree;
419 node = &entry->rb_node;
420 rb_erase(node, &tree->tree);
421 tree->last = NULL;
422 set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
423
424 spin_lock(&root->fs_info->ordered_extent_lock);
425 list_del_init(&entry->root_extent_list);
426
427 trace_btrfs_ordered_extent_remove(inode, entry);
428
429 /*
430 * we have no more ordered extents for this inode and
431 * no dirty pages. We can safely remove it from the
432 * list of ordered extents
433 */
434 if (RB_EMPTY_ROOT(&tree->tree) &&
435 !mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY)) {
436 list_del_init(&BTRFS_I(inode)->ordered_operations);
437 }
438 spin_unlock(&root->fs_info->ordered_extent_lock);
439
440 return 0;
441}
442
443/*
444 * remove an ordered extent from the tree. No references are dropped
445 * but any waiters are woken.
446 */
447int btrfs_remove_ordered_extent(struct inode *inode,
448 struct btrfs_ordered_extent *entry)
449{
450 struct btrfs_ordered_inode_tree *tree;
451 int ret;
452
453 tree = &BTRFS_I(inode)->ordered_tree;
454 spin_lock(&tree->lock);
455 ret = __btrfs_remove_ordered_extent(inode, entry);
456 spin_unlock(&tree->lock);
457 wake_up(&entry->wait);
458
459 return ret;
460}
461
462/*
463 * wait for all the ordered extents in a root. This is done when balancing
464 * space between drives.
465 */
466int btrfs_wait_ordered_extents(struct btrfs_root *root,
467 int nocow_only, int delay_iput)
468{
469 struct list_head splice;
470 struct list_head *cur;
471 struct btrfs_ordered_extent *ordered;
472 struct inode *inode;
473
474 INIT_LIST_HEAD(&splice);
475
476 spin_lock(&root->fs_info->ordered_extent_lock);
477 list_splice_init(&root->fs_info->ordered_extents, &splice);
478 while (!list_empty(&splice)) {
479 cur = splice.next;
480 ordered = list_entry(cur, struct btrfs_ordered_extent,
481 root_extent_list);
482 if (nocow_only &&
483 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags) &&
484 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) {
485 list_move(&ordered->root_extent_list,
486 &root->fs_info->ordered_extents);
487 cond_resched_lock(&root->fs_info->ordered_extent_lock);
488 continue;
489 }
490
491 list_del_init(&ordered->root_extent_list);
492 atomic_inc(&ordered->refs);
493
494 /*
495 * the inode may be getting freed (in sys_unlink path).
496 */
497 inode = igrab(ordered->inode);
498
499 spin_unlock(&root->fs_info->ordered_extent_lock);
500
501 if (inode) {
502 btrfs_start_ordered_extent(inode, ordered, 1);
503 btrfs_put_ordered_extent(ordered);
504 if (delay_iput)
505 btrfs_add_delayed_iput(inode);
506 else
507 iput(inode);
508 } else {
509 btrfs_put_ordered_extent(ordered);
510 }
511
512 spin_lock(&root->fs_info->ordered_extent_lock);
513 }
514 spin_unlock(&root->fs_info->ordered_extent_lock);
515 return 0;
516}
517
518/*
519 * this is used during transaction commit to write all the inodes
520 * added to the ordered operation list. These files must be fully on
521 * disk before the transaction commits.
522 *
523 * we have two modes here, one is to just start the IO via filemap_flush
524 * and the other is to wait for all the io. When we wait, we have an
525 * extra check to make sure the ordered operation list really is empty
526 * before we return
527 */
528int btrfs_run_ordered_operations(struct btrfs_root *root, int wait)
529{
530 struct btrfs_inode *btrfs_inode;
531 struct inode *inode;
532 struct list_head splice;
533
534 INIT_LIST_HEAD(&splice);
535
536 mutex_lock(&root->fs_info->ordered_operations_mutex);
537 spin_lock(&root->fs_info->ordered_extent_lock);
538again:
539 list_splice_init(&root->fs_info->ordered_operations, &splice);
540
541 while (!list_empty(&splice)) {
542 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
543 ordered_operations);
544
545 inode = &btrfs_inode->vfs_inode;
546
547 list_del_init(&btrfs_inode->ordered_operations);
548
549 /*
550 * the inode may be getting freed (in sys_unlink path).
551 */
552 inode = igrab(inode);
553
554 if (!wait && inode) {
555 list_add_tail(&BTRFS_I(inode)->ordered_operations,
556 &root->fs_info->ordered_operations);
557 }
558 spin_unlock(&root->fs_info->ordered_extent_lock);
559
560 if (inode) {
561 if (wait)
562 btrfs_wait_ordered_range(inode, 0, (u64)-1);
563 else
564 filemap_flush(inode->i_mapping);
565 btrfs_add_delayed_iput(inode);
566 }
567
568 cond_resched();
569 spin_lock(&root->fs_info->ordered_extent_lock);
570 }
571 if (wait && !list_empty(&root->fs_info->ordered_operations))
572 goto again;
573
574 spin_unlock(&root->fs_info->ordered_extent_lock);
575 mutex_unlock(&root->fs_info->ordered_operations_mutex);
576
577 return 0;
578}
579
580/*
581 * Used to start IO or wait for a given ordered extent to finish.
582 *
583 * If wait is one, this effectively waits on page writeback for all the pages
584 * in the extent, and it waits on the io completion code to insert
585 * metadata into the btree corresponding to the extent
586 */
587void btrfs_start_ordered_extent(struct inode *inode,
588 struct btrfs_ordered_extent *entry,
589 int wait)
590{
591 u64 start = entry->file_offset;
592 u64 end = start + entry->len - 1;
593
594 trace_btrfs_ordered_extent_start(inode, entry);
595
596 /*
597 * pages in the range can be dirty, clean or writeback. We
598 * start IO on any dirty ones so the wait doesn't stall waiting
599 * for pdflush to find them
600 */
601 if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
602 filemap_fdatawrite_range(inode->i_mapping, start, end);
603 if (wait) {
604 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
605 &entry->flags));
606 }
607}
608
609/*
610 * Used to wait on ordered extents across a large range of bytes.
611 */
612int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
613{
614 u64 end;
615 u64 orig_end;
616 struct btrfs_ordered_extent *ordered;
617 int found;
618
619 if (start + len < start) {
620 orig_end = INT_LIMIT(loff_t);
621 } else {
622 orig_end = start + len - 1;
623 if (orig_end > INT_LIMIT(loff_t))
624 orig_end = INT_LIMIT(loff_t);
625 }
626again:
627 /* start IO across the range first to instantiate any delalloc
628 * extents
629 */
630 filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
631
632 /* The compression code will leave pages locked but return from
633 * writepage without setting the page writeback. Starting again
634 * with WB_SYNC_ALL will end up waiting for the IO to actually start.
635 */
636 filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
637
638 filemap_fdatawait_range(inode->i_mapping, start, orig_end);
639
640 end = orig_end;
641 found = 0;
642 while (1) {
643 ordered = btrfs_lookup_first_ordered_extent(inode, end);
644 if (!ordered)
645 break;
646 if (ordered->file_offset > orig_end) {
647 btrfs_put_ordered_extent(ordered);
648 break;
649 }
650 if (ordered->file_offset + ordered->len < start) {
651 btrfs_put_ordered_extent(ordered);
652 break;
653 }
654 found++;
655 btrfs_start_ordered_extent(inode, ordered, 1);
656 end = ordered->file_offset;
657 btrfs_put_ordered_extent(ordered);
658 if (end == 0 || end == start)
659 break;
660 end--;
661 }
662 if (found || test_range_bit(&BTRFS_I(inode)->io_tree, start, orig_end,
663 EXTENT_DELALLOC, 0, NULL)) {
664 schedule_timeout(1);
665 goto again;
666 }
667 return 0;
668}
669
670/*
671 * find an ordered extent corresponding to file_offset. return NULL if
672 * nothing is found, otherwise take a reference on the extent and return it
673 */
674struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
675 u64 file_offset)
676{
677 struct btrfs_ordered_inode_tree *tree;
678 struct rb_node *node;
679 struct btrfs_ordered_extent *entry = NULL;
680
681 tree = &BTRFS_I(inode)->ordered_tree;
682 spin_lock(&tree->lock);
683 node = tree_search(tree, file_offset);
684 if (!node)
685 goto out;
686
687 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
688 if (!offset_in_entry(entry, file_offset))
689 entry = NULL;
690 if (entry)
691 atomic_inc(&entry->refs);
692out:
693 spin_unlock(&tree->lock);
694 return entry;
695}
696
697/* Since the DIO code tries to lock a wide area we need to look for any ordered
698 * extents that exist in the range, rather than just the start of the range.
699 */
700struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
701 u64 file_offset,
702 u64 len)
703{
704 struct btrfs_ordered_inode_tree *tree;
705 struct rb_node *node;
706 struct btrfs_ordered_extent *entry = NULL;
707
708 tree = &BTRFS_I(inode)->ordered_tree;
709 spin_lock(&tree->lock);
710 node = tree_search(tree, file_offset);
711 if (!node) {
712 node = tree_search(tree, file_offset + len);
713 if (!node)
714 goto out;
715 }
716
717 while (1) {
718 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
719 if (range_overlaps(entry, file_offset, len))
720 break;
721
722 if (entry->file_offset >= file_offset + len) {
723 entry = NULL;
724 break;
725 }
726 entry = NULL;
727 node = rb_next(node);
728 if (!node)
729 break;
730 }
731out:
732 if (entry)
733 atomic_inc(&entry->refs);
734 spin_unlock(&tree->lock);
735 return entry;
736}
737
738/*
739 * lookup and return any extent before 'file_offset'. NULL is returned
740 * if none is found
741 */
742struct btrfs_ordered_extent *
743btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
744{
745 struct btrfs_ordered_inode_tree *tree;
746 struct rb_node *node;
747 struct btrfs_ordered_extent *entry = NULL;
748
749 tree = &BTRFS_I(inode)->ordered_tree;
750 spin_lock(&tree->lock);
751 node = tree_search(tree, file_offset);
752 if (!node)
753 goto out;
754
755 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
756 atomic_inc(&entry->refs);
757out:
758 spin_unlock(&tree->lock);
759 return entry;
760}
761
762/*
763 * After an extent is done, call this to conditionally update the on disk
764 * i_size. i_size is updated to cover any fully written part of the file.
765 */
766int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
767 struct btrfs_ordered_extent *ordered)
768{
769 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
770 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
771 u64 disk_i_size;
772 u64 new_i_size;
773 u64 i_size_test;
774 u64 i_size = i_size_read(inode);
775 struct rb_node *node;
776 struct rb_node *prev = NULL;
777 struct btrfs_ordered_extent *test;
778 int ret = 1;
779
780 if (ordered)
781 offset = entry_end(ordered);
782 else
783 offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize);
784
785 spin_lock(&tree->lock);
786 disk_i_size = BTRFS_I(inode)->disk_i_size;
787
788 /* truncate file */
789 if (disk_i_size > i_size) {
790 BTRFS_I(inode)->disk_i_size = i_size;
791 ret = 0;
792 goto out;
793 }
794
795 /*
796 * if the disk i_size is already at the inode->i_size, or
797 * this ordered extent is inside the disk i_size, we're done
798 */
799 if (disk_i_size == i_size || offset <= disk_i_size) {
800 goto out;
801 }
802
803 /*
804 * we can't update the disk_isize if there are delalloc bytes
805 * between disk_i_size and this ordered extent
806 */
807 if (test_range_bit(io_tree, disk_i_size, offset - 1,
808 EXTENT_DELALLOC, 0, NULL)) {
809 goto out;
810 }
811 /*
812 * walk backward from this ordered extent to disk_i_size.
813 * if we find an ordered extent then we can't update disk i_size
814 * yet
815 */
816 if (ordered) {
817 node = rb_prev(&ordered->rb_node);
818 } else {
819 prev = tree_search(tree, offset);
820 /*
821 * we insert file extents without involving ordered struct,
822 * so there should be no ordered struct cover this offset
823 */
824 if (prev) {
825 test = rb_entry(prev, struct btrfs_ordered_extent,
826 rb_node);
827 BUG_ON(offset_in_entry(test, offset));
828 }
829 node = prev;
830 }
831 while (node) {
832 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
833 if (test->file_offset + test->len <= disk_i_size)
834 break;
835 if (test->file_offset >= i_size)
836 break;
837 if (test->file_offset >= disk_i_size)
838 goto out;
839 node = rb_prev(node);
840 }
841 new_i_size = min_t(u64, offset, i_size);
842
843 /*
844 * at this point, we know we can safely update i_size to at least
845 * the offset from this ordered extent. But, we need to
846 * walk forward and see if ios from higher up in the file have
847 * finished.
848 */
849 if (ordered) {
850 node = rb_next(&ordered->rb_node);
851 } else {
852 if (prev)
853 node = rb_next(prev);
854 else
855 node = rb_first(&tree->tree);
856 }
857 i_size_test = 0;
858 if (node) {
859 /*
860 * do we have an area where IO might have finished
861 * between our ordered extent and the next one.
862 */
863 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
864 if (test->file_offset > offset)
865 i_size_test = test->file_offset;
866 } else {
867 i_size_test = i_size;
868 }
869
870 /*
871 * i_size_test is the end of a region after this ordered
872 * extent where there are no ordered extents. As long as there
873 * are no delalloc bytes in this area, it is safe to update
874 * disk_i_size to the end of the region.
875 */
876 if (i_size_test > offset &&
877 !test_range_bit(io_tree, offset, i_size_test - 1,
878 EXTENT_DELALLOC, 0, NULL)) {
879 new_i_size = min_t(u64, i_size_test, i_size);
880 }
881 BTRFS_I(inode)->disk_i_size = new_i_size;
882 ret = 0;
883out:
884 /*
885 * we need to remove the ordered extent with the tree lock held
886 * so that other people calling this function don't find our fully
887 * processed ordered entry and skip updating the i_size
888 */
889 if (ordered)
890 __btrfs_remove_ordered_extent(inode, ordered);
891 spin_unlock(&tree->lock);
892 if (ordered)
893 wake_up(&ordered->wait);
894 return ret;
895}
896
897/*
898 * search the ordered extents for one corresponding to 'offset' and
899 * try to find a checksum. This is used because we allow pages to
900 * be reclaimed before their checksum is actually put into the btree
901 */
902int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
903 u32 *sum)
904{
905 struct btrfs_ordered_sum *ordered_sum;
906 struct btrfs_sector_sum *sector_sums;
907 struct btrfs_ordered_extent *ordered;
908 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
909 unsigned long num_sectors;
910 unsigned long i;
911 u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
912 int ret = 1;
913
914 ordered = btrfs_lookup_ordered_extent(inode, offset);
915 if (!ordered)
916 return 1;
917
918 spin_lock(&tree->lock);
919 list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
920 if (disk_bytenr >= ordered_sum->bytenr) {
921 num_sectors = ordered_sum->len / sectorsize;
922 sector_sums = ordered_sum->sums;
923 for (i = 0; i < num_sectors; i++) {
924 if (sector_sums[i].bytenr == disk_bytenr) {
925 *sum = sector_sums[i].sum;
926 ret = 0;
927 goto out;
928 }
929 }
930 }
931 }
932out:
933 spin_unlock(&tree->lock);
934 btrfs_put_ordered_extent(ordered);
935 return ret;
936}
937
938
939/*
940 * add a given inode to the list of inodes that must be fully on
941 * disk before a transaction commit finishes.
942 *
943 * This basically gives us the ext3 style data=ordered mode, and it is mostly
944 * used to make sure renamed files are fully on disk.
945 *
946 * It is a noop if the inode is already fully on disk.
947 *
948 * If trans is not null, we'll do a friendly check for a transaction that
949 * is already flushing things and force the IO down ourselves.
950 */
951int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
952 struct btrfs_root *root,
953 struct inode *inode)
954{
955 u64 last_mod;
956
957 last_mod = max(BTRFS_I(inode)->generation, BTRFS_I(inode)->last_trans);
958
959 /*
960 * if this file hasn't been changed since the last transaction
961 * commit, we can safely return without doing anything
962 */
963 if (last_mod < root->fs_info->last_trans_committed)
964 return 0;
965
966 /*
967 * the transaction is already committing. Just start the IO and
968 * don't bother with all of this list nonsense
969 */
970 if (trans && root->fs_info->running_transaction->blocked) {
971 btrfs_wait_ordered_range(inode, 0, (u64)-1);
972 return 0;
973 }
974
975 spin_lock(&root->fs_info->ordered_extent_lock);
976 if (list_empty(&BTRFS_I(inode)->ordered_operations)) {
977 list_add_tail(&BTRFS_I(inode)->ordered_operations,
978 &root->fs_info->ordered_operations);
979 }
980 spin_unlock(&root->fs_info->ordered_extent_lock);
981
982 return 0;
983}
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 "messages.h"
11#include "misc.h"
12#include "ctree.h"
13#include "transaction.h"
14#include "btrfs_inode.h"
15#include "extent_io.h"
16#include "disk-io.h"
17#include "compression.h"
18#include "delalloc-space.h"
19#include "qgroup.h"
20#include "subpage.h"
21#include "file.h"
22#include "block-group.h"
23
24static struct kmem_cache *btrfs_ordered_extent_cache;
25
26static u64 entry_end(struct btrfs_ordered_extent *entry)
27{
28 if (entry->file_offset + entry->num_bytes < entry->file_offset)
29 return (u64)-1;
30 return entry->file_offset + entry->num_bytes;
31}
32
33/* returns NULL if the insertion worked, or it returns the node it did find
34 * in the tree
35 */
36static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
37 struct rb_node *node)
38{
39 struct rb_node **p = &root->rb_node;
40 struct rb_node *parent = NULL;
41 struct btrfs_ordered_extent *entry;
42
43 while (*p) {
44 parent = *p;
45 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
46
47 if (file_offset < entry->file_offset)
48 p = &(*p)->rb_left;
49 else if (file_offset >= entry_end(entry))
50 p = &(*p)->rb_right;
51 else
52 return parent;
53 }
54
55 rb_link_node(node, parent, p);
56 rb_insert_color(node, root);
57 return NULL;
58}
59
60/*
61 * look for a given offset in the tree, and if it can't be found return the
62 * first lesser offset
63 */
64static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
65 struct rb_node **prev_ret)
66{
67 struct rb_node *n = root->rb_node;
68 struct rb_node *prev = NULL;
69 struct rb_node *test;
70 struct btrfs_ordered_extent *entry;
71 struct btrfs_ordered_extent *prev_entry = NULL;
72
73 while (n) {
74 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
75 prev = n;
76 prev_entry = entry;
77
78 if (file_offset < entry->file_offset)
79 n = n->rb_left;
80 else if (file_offset >= entry_end(entry))
81 n = n->rb_right;
82 else
83 return n;
84 }
85 if (!prev_ret)
86 return NULL;
87
88 while (prev && file_offset >= entry_end(prev_entry)) {
89 test = rb_next(prev);
90 if (!test)
91 break;
92 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
93 rb_node);
94 if (file_offset < entry_end(prev_entry))
95 break;
96
97 prev = test;
98 }
99 if (prev)
100 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
101 rb_node);
102 while (prev && file_offset < entry_end(prev_entry)) {
103 test = rb_prev(prev);
104 if (!test)
105 break;
106 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
107 rb_node);
108 prev = test;
109 }
110 *prev_ret = prev;
111 return NULL;
112}
113
114static int btrfs_range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
115 u64 len)
116{
117 if (file_offset + len <= entry->file_offset ||
118 entry->file_offset + entry->num_bytes <= file_offset)
119 return 0;
120 return 1;
121}
122
123/*
124 * look find the first ordered struct that has this offset, otherwise
125 * the first one less than this offset
126 */
127static inline struct rb_node *ordered_tree_search(struct btrfs_inode *inode,
128 u64 file_offset)
129{
130 struct rb_node *prev = NULL;
131 struct rb_node *ret;
132 struct btrfs_ordered_extent *entry;
133
134 if (inode->ordered_tree_last) {
135 entry = rb_entry(inode->ordered_tree_last, struct btrfs_ordered_extent,
136 rb_node);
137 if (in_range(file_offset, entry->file_offset, entry->num_bytes))
138 return inode->ordered_tree_last;
139 }
140 ret = __tree_search(&inode->ordered_tree, file_offset, &prev);
141 if (!ret)
142 ret = prev;
143 if (ret)
144 inode->ordered_tree_last = ret;
145 return ret;
146}
147
148static struct btrfs_ordered_extent *alloc_ordered_extent(
149 struct btrfs_inode *inode, u64 file_offset, u64 num_bytes,
150 u64 ram_bytes, u64 disk_bytenr, u64 disk_num_bytes,
151 u64 offset, unsigned long flags, int compress_type)
152{
153 struct btrfs_ordered_extent *entry;
154 int ret;
155 u64 qgroup_rsv = 0;
156
157 if (flags &
158 ((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
159 /* For nocow write, we can release the qgroup rsv right now */
160 ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes, &qgroup_rsv);
161 if (ret < 0)
162 return ERR_PTR(ret);
163 } else {
164 /*
165 * The ordered extent has reserved qgroup space, release now
166 * and pass the reserved number for qgroup_record to free.
167 */
168 ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes, &qgroup_rsv);
169 if (ret < 0)
170 return ERR_PTR(ret);
171 }
172 entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
173 if (!entry)
174 return ERR_PTR(-ENOMEM);
175
176 entry->file_offset = file_offset;
177 entry->num_bytes = num_bytes;
178 entry->ram_bytes = ram_bytes;
179 entry->disk_bytenr = disk_bytenr;
180 entry->disk_num_bytes = disk_num_bytes;
181 entry->offset = offset;
182 entry->bytes_left = num_bytes;
183 entry->inode = BTRFS_I(igrab(&inode->vfs_inode));
184 entry->compress_type = compress_type;
185 entry->truncated_len = (u64)-1;
186 entry->qgroup_rsv = qgroup_rsv;
187 entry->flags = flags;
188 refcount_set(&entry->refs, 1);
189 init_waitqueue_head(&entry->wait);
190 INIT_LIST_HEAD(&entry->list);
191 INIT_LIST_HEAD(&entry->log_list);
192 INIT_LIST_HEAD(&entry->root_extent_list);
193 INIT_LIST_HEAD(&entry->work_list);
194 INIT_LIST_HEAD(&entry->bioc_list);
195 init_completion(&entry->completion);
196
197 /*
198 * We don't need the count_max_extents here, we can assume that all of
199 * that work has been done at higher layers, so this is truly the
200 * smallest the extent is going to get.
201 */
202 spin_lock(&inode->lock);
203 btrfs_mod_outstanding_extents(inode, 1);
204 spin_unlock(&inode->lock);
205
206 return entry;
207}
208
209static void insert_ordered_extent(struct btrfs_ordered_extent *entry)
210{
211 struct btrfs_inode *inode = entry->inode;
212 struct btrfs_root *root = inode->root;
213 struct btrfs_fs_info *fs_info = root->fs_info;
214 struct rb_node *node;
215
216 trace_btrfs_ordered_extent_add(inode, entry);
217
218 percpu_counter_add_batch(&fs_info->ordered_bytes, entry->num_bytes,
219 fs_info->delalloc_batch);
220
221 /* One ref for the tree. */
222 refcount_inc(&entry->refs);
223
224 spin_lock_irq(&inode->ordered_tree_lock);
225 node = tree_insert(&inode->ordered_tree, entry->file_offset,
226 &entry->rb_node);
227 if (unlikely(node))
228 btrfs_panic(fs_info, -EEXIST,
229 "inconsistency in ordered tree at offset %llu",
230 entry->file_offset);
231 spin_unlock_irq(&inode->ordered_tree_lock);
232
233 spin_lock(&root->ordered_extent_lock);
234 list_add_tail(&entry->root_extent_list,
235 &root->ordered_extents);
236 root->nr_ordered_extents++;
237 if (root->nr_ordered_extents == 1) {
238 spin_lock(&fs_info->ordered_root_lock);
239 BUG_ON(!list_empty(&root->ordered_root));
240 list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
241 spin_unlock(&fs_info->ordered_root_lock);
242 }
243 spin_unlock(&root->ordered_extent_lock);
244}
245
246/*
247 * Add an ordered extent to the per-inode tree.
248 *
249 * @inode: Inode that this extent is for.
250 * @file_offset: Logical offset in file where the extent starts.
251 * @num_bytes: Logical length of extent in file.
252 * @ram_bytes: Full length of unencoded data.
253 * @disk_bytenr: Offset of extent on disk.
254 * @disk_num_bytes: Size of extent on disk.
255 * @offset: Offset into unencoded data where file data starts.
256 * @flags: Flags specifying type of extent (1 << BTRFS_ORDERED_*).
257 * @compress_type: Compression algorithm used for data.
258 *
259 * Most of these parameters correspond to &struct btrfs_file_extent_item. The
260 * tree is given a single reference on the ordered extent that was inserted, and
261 * the returned pointer is given a second reference.
262 *
263 * Return: the new ordered extent or error pointer.
264 */
265struct btrfs_ordered_extent *btrfs_alloc_ordered_extent(
266 struct btrfs_inode *inode, u64 file_offset,
267 const struct btrfs_file_extent *file_extent, unsigned long flags)
268{
269 struct btrfs_ordered_extent *entry;
270
271 ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
272
273 /*
274 * For regular writes, we just use the members in @file_extent.
275 *
276 * For NOCOW, we don't really care about the numbers except @start and
277 * file_extent->num_bytes, as we won't insert a file extent item at all.
278 *
279 * For PREALLOC, we do not use ordered extent members, but
280 * btrfs_mark_extent_written() handles everything.
281 *
282 * So here we always pass 0 as offset for NOCOW/PREALLOC ordered extents,
283 * or btrfs_split_ordered_extent() cannot handle it correctly.
284 */
285 if (flags & ((1U << BTRFS_ORDERED_NOCOW) | (1U << BTRFS_ORDERED_PREALLOC)))
286 entry = alloc_ordered_extent(inode, file_offset,
287 file_extent->num_bytes,
288 file_extent->num_bytes,
289 file_extent->disk_bytenr + file_extent->offset,
290 file_extent->num_bytes, 0, flags,
291 file_extent->compression);
292 else
293 entry = alloc_ordered_extent(inode, file_offset,
294 file_extent->num_bytes,
295 file_extent->ram_bytes,
296 file_extent->disk_bytenr,
297 file_extent->disk_num_bytes,
298 file_extent->offset, flags,
299 file_extent->compression);
300 if (!IS_ERR(entry))
301 insert_ordered_extent(entry);
302 return entry;
303}
304
305/*
306 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
307 * when an ordered extent is finished. If the list covers more than one
308 * ordered extent, it is split across multiples.
309 */
310void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
311 struct btrfs_ordered_sum *sum)
312{
313 struct btrfs_inode *inode = entry->inode;
314
315 spin_lock_irq(&inode->ordered_tree_lock);
316 list_add_tail(&sum->list, &entry->list);
317 spin_unlock_irq(&inode->ordered_tree_lock);
318}
319
320void btrfs_mark_ordered_extent_error(struct btrfs_ordered_extent *ordered)
321{
322 if (!test_and_set_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
323 mapping_set_error(ordered->inode->vfs_inode.i_mapping, -EIO);
324}
325
326static void finish_ordered_fn(struct btrfs_work *work)
327{
328 struct btrfs_ordered_extent *ordered_extent;
329
330 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
331 btrfs_finish_ordered_io(ordered_extent);
332}
333
334static bool can_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
335 struct folio *folio, u64 file_offset,
336 u64 len, bool uptodate)
337{
338 struct btrfs_inode *inode = ordered->inode;
339 struct btrfs_fs_info *fs_info = inode->root->fs_info;
340
341 lockdep_assert_held(&inode->ordered_tree_lock);
342
343 if (folio) {
344 ASSERT(folio->mapping);
345 ASSERT(folio_pos(folio) <= file_offset);
346 ASSERT(file_offset + len <= folio_pos(folio) + folio_size(folio));
347
348 /*
349 * Ordered flag indicates whether we still have
350 * pending io unfinished for the ordered extent.
351 *
352 * If it's not set, we need to skip to next range.
353 */
354 if (!btrfs_folio_test_ordered(fs_info, folio, file_offset, len))
355 return false;
356 btrfs_folio_clear_ordered(fs_info, folio, file_offset, len);
357 }
358
359 /* Now we're fine to update the accounting. */
360 if (WARN_ON_ONCE(len > ordered->bytes_left)) {
361 btrfs_crit(fs_info,
362"bad ordered extent accounting, root=%llu ino=%llu OE offset=%llu OE len=%llu to_dec=%llu left=%llu",
363 btrfs_root_id(inode->root), btrfs_ino(inode),
364 ordered->file_offset, ordered->num_bytes,
365 len, ordered->bytes_left);
366 ordered->bytes_left = 0;
367 } else {
368 ordered->bytes_left -= len;
369 }
370
371 if (!uptodate)
372 set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
373
374 if (ordered->bytes_left)
375 return false;
376
377 /*
378 * All the IO of the ordered extent is finished, we need to queue
379 * the finish_func to be executed.
380 */
381 set_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags);
382 cond_wake_up(&ordered->wait);
383 refcount_inc(&ordered->refs);
384 trace_btrfs_ordered_extent_mark_finished(inode, ordered);
385 return true;
386}
387
388static void btrfs_queue_ordered_fn(struct btrfs_ordered_extent *ordered)
389{
390 struct btrfs_inode *inode = ordered->inode;
391 struct btrfs_fs_info *fs_info = inode->root->fs_info;
392 struct btrfs_workqueue *wq = btrfs_is_free_space_inode(inode) ?
393 fs_info->endio_freespace_worker : fs_info->endio_write_workers;
394
395 btrfs_init_work(&ordered->work, finish_ordered_fn, NULL);
396 btrfs_queue_work(wq, &ordered->work);
397}
398
399void btrfs_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
400 struct folio *folio, u64 file_offset, u64 len,
401 bool uptodate)
402{
403 struct btrfs_inode *inode = ordered->inode;
404 unsigned long flags;
405 bool ret;
406
407 trace_btrfs_finish_ordered_extent(inode, file_offset, len, uptodate);
408
409 spin_lock_irqsave(&inode->ordered_tree_lock, flags);
410 ret = can_finish_ordered_extent(ordered, folio, file_offset, len,
411 uptodate);
412 spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
413
414 /*
415 * If this is a COW write it means we created new extent maps for the
416 * range and they point to unwritten locations if we got an error either
417 * before submitting a bio or during IO.
418 *
419 * We have marked the ordered extent with BTRFS_ORDERED_IOERR, and we
420 * are queuing its completion below. During completion, at
421 * btrfs_finish_one_ordered(), we will drop the extent maps for the
422 * unwritten extents.
423 *
424 * However because completion runs in a work queue we can end up having
425 * a fast fsync running before that. In the case of direct IO, once we
426 * unlock the inode the fsync might start, and we queue the completion
427 * before unlocking the inode. In the case of buffered IO when writeback
428 * finishes (end_bbio_data_write()) we queue the completion, so if the
429 * writeback was triggered by a fast fsync, the fsync might start
430 * logging before ordered extent completion runs in the work queue.
431 *
432 * The fast fsync will log file extent items based on the extent maps it
433 * finds, so if by the time it collects extent maps the ordered extent
434 * completion didn't happen yet, it will log file extent items that
435 * point to unwritten extents, resulting in a corruption if a crash
436 * happens and the log tree is replayed. Note that a fast fsync does not
437 * wait for completion of ordered extents in order to reduce latency.
438 *
439 * Set a flag in the inode so that the next fast fsync will wait for
440 * ordered extents to complete before starting to log.
441 */
442 if (!uptodate && !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
443 set_bit(BTRFS_INODE_COW_WRITE_ERROR, &inode->runtime_flags);
444
445 if (ret)
446 btrfs_queue_ordered_fn(ordered);
447}
448
449/*
450 * Mark all ordered extents io inside the specified range finished.
451 *
452 * @folio: The involved folio for the operation.
453 * For uncompressed buffered IO, the folio status also needs to be
454 * updated to indicate whether the pending ordered io is finished.
455 * Can be NULL for direct IO and compressed write.
456 * For these cases, callers are ensured they won't execute the
457 * endio function twice.
458 *
459 * This function is called for endio, thus the range must have ordered
460 * extent(s) covering it.
461 */
462void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
463 struct folio *folio, u64 file_offset,
464 u64 num_bytes, bool uptodate)
465{
466 struct rb_node *node;
467 struct btrfs_ordered_extent *entry = NULL;
468 unsigned long flags;
469 u64 cur = file_offset;
470
471 trace_btrfs_writepage_end_io_hook(inode, file_offset,
472 file_offset + num_bytes - 1,
473 uptodate);
474
475 spin_lock_irqsave(&inode->ordered_tree_lock, flags);
476 while (cur < file_offset + num_bytes) {
477 u64 entry_end;
478 u64 end;
479 u32 len;
480
481 node = ordered_tree_search(inode, cur);
482 /* No ordered extents at all */
483 if (!node)
484 break;
485
486 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
487 entry_end = entry->file_offset + entry->num_bytes;
488 /*
489 * |<-- OE --->| |
490 * cur
491 * Go to next OE.
492 */
493 if (cur >= entry_end) {
494 node = rb_next(node);
495 /* No more ordered extents, exit */
496 if (!node)
497 break;
498 entry = rb_entry(node, struct btrfs_ordered_extent,
499 rb_node);
500
501 /* Go to next ordered extent and continue */
502 cur = entry->file_offset;
503 continue;
504 }
505 /*
506 * | |<--- OE --->|
507 * cur
508 * Go to the start of OE.
509 */
510 if (cur < entry->file_offset) {
511 cur = entry->file_offset;
512 continue;
513 }
514
515 /*
516 * Now we are definitely inside one ordered extent.
517 *
518 * |<--- OE --->|
519 * |
520 * cur
521 */
522 end = min(entry->file_offset + entry->num_bytes,
523 file_offset + num_bytes) - 1;
524 ASSERT(end + 1 - cur < U32_MAX);
525 len = end + 1 - cur;
526
527 if (can_finish_ordered_extent(entry, folio, cur, len, uptodate)) {
528 spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
529 btrfs_queue_ordered_fn(entry);
530 spin_lock_irqsave(&inode->ordered_tree_lock, flags);
531 }
532 cur += len;
533 }
534 spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
535}
536
537/*
538 * Finish IO for one ordered extent across a given range. The range can only
539 * contain one ordered extent.
540 *
541 * @cached: The cached ordered extent. If not NULL, we can skip the tree
542 * search and use the ordered extent directly.
543 * Will be also used to store the finished ordered extent.
544 * @file_offset: File offset for the finished IO
545 * @io_size: Length of the finish IO range
546 *
547 * Return true if the ordered extent is finished in the range, and update
548 * @cached.
549 * Return false otherwise.
550 *
551 * NOTE: The range can NOT cross multiple ordered extents.
552 * Thus caller should ensure the range doesn't cross ordered extents.
553 */
554bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
555 struct btrfs_ordered_extent **cached,
556 u64 file_offset, u64 io_size)
557{
558 struct rb_node *node;
559 struct btrfs_ordered_extent *entry = NULL;
560 unsigned long flags;
561 bool finished = false;
562
563 spin_lock_irqsave(&inode->ordered_tree_lock, flags);
564 if (cached && *cached) {
565 entry = *cached;
566 goto have_entry;
567 }
568
569 node = ordered_tree_search(inode, file_offset);
570 if (!node)
571 goto out;
572
573 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
574have_entry:
575 if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
576 goto out;
577
578 if (io_size > entry->bytes_left)
579 btrfs_crit(inode->root->fs_info,
580 "bad ordered accounting left %llu size %llu",
581 entry->bytes_left, io_size);
582
583 entry->bytes_left -= io_size;
584
585 if (entry->bytes_left == 0) {
586 /*
587 * Ensure only one caller can set the flag and finished_ret
588 * accordingly
589 */
590 finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
591 /* test_and_set_bit implies a barrier */
592 cond_wake_up_nomb(&entry->wait);
593 }
594out:
595 if (finished && cached && entry) {
596 *cached = entry;
597 refcount_inc(&entry->refs);
598 trace_btrfs_ordered_extent_dec_test_pending(inode, entry);
599 }
600 spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
601 return finished;
602}
603
604/*
605 * used to drop a reference on an ordered extent. This will free
606 * the extent if the last reference is dropped
607 */
608void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
609{
610 struct list_head *cur;
611 struct btrfs_ordered_sum *sum;
612
613 trace_btrfs_ordered_extent_put(entry->inode, entry);
614
615 if (refcount_dec_and_test(&entry->refs)) {
616 ASSERT(list_empty(&entry->root_extent_list));
617 ASSERT(list_empty(&entry->log_list));
618 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
619 if (entry->inode)
620 btrfs_add_delayed_iput(entry->inode);
621 while (!list_empty(&entry->list)) {
622 cur = entry->list.next;
623 sum = list_entry(cur, struct btrfs_ordered_sum, list);
624 list_del(&sum->list);
625 kvfree(sum);
626 }
627 kmem_cache_free(btrfs_ordered_extent_cache, entry);
628 }
629}
630
631/*
632 * remove an ordered extent from the tree. No references are dropped
633 * and waiters are woken up.
634 */
635void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
636 struct btrfs_ordered_extent *entry)
637{
638 struct btrfs_root *root = btrfs_inode->root;
639 struct btrfs_fs_info *fs_info = root->fs_info;
640 struct rb_node *node;
641 bool pending;
642 bool freespace_inode;
643
644 /*
645 * If this is a free space inode the thread has not acquired the ordered
646 * extents lockdep map.
647 */
648 freespace_inode = btrfs_is_free_space_inode(btrfs_inode);
649
650 btrfs_lockdep_acquire(fs_info, btrfs_trans_pending_ordered);
651 /* This is paired with alloc_ordered_extent(). */
652 spin_lock(&btrfs_inode->lock);
653 btrfs_mod_outstanding_extents(btrfs_inode, -1);
654 spin_unlock(&btrfs_inode->lock);
655 if (root != fs_info->tree_root) {
656 u64 release;
657
658 if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
659 release = entry->disk_num_bytes;
660 else
661 release = entry->num_bytes;
662 btrfs_delalloc_release_metadata(btrfs_inode, release,
663 test_bit(BTRFS_ORDERED_IOERR,
664 &entry->flags));
665 }
666
667 percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
668 fs_info->delalloc_batch);
669
670 spin_lock_irq(&btrfs_inode->ordered_tree_lock);
671 node = &entry->rb_node;
672 rb_erase(node, &btrfs_inode->ordered_tree);
673 RB_CLEAR_NODE(node);
674 if (btrfs_inode->ordered_tree_last == node)
675 btrfs_inode->ordered_tree_last = NULL;
676 set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
677 pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
678 spin_unlock_irq(&btrfs_inode->ordered_tree_lock);
679
680 /*
681 * The current running transaction is waiting on us, we need to let it
682 * know that we're complete and wake it up.
683 */
684 if (pending) {
685 struct btrfs_transaction *trans;
686
687 /*
688 * The checks for trans are just a formality, it should be set,
689 * but if it isn't we don't want to deref/assert under the spin
690 * lock, so be nice and check if trans is set, but ASSERT() so
691 * if it isn't set a developer will notice.
692 */
693 spin_lock(&fs_info->trans_lock);
694 trans = fs_info->running_transaction;
695 if (trans)
696 refcount_inc(&trans->use_count);
697 spin_unlock(&fs_info->trans_lock);
698
699 ASSERT(trans || BTRFS_FS_ERROR(fs_info));
700 if (trans) {
701 if (atomic_dec_and_test(&trans->pending_ordered))
702 wake_up(&trans->pending_wait);
703 btrfs_put_transaction(trans);
704 }
705 }
706
707 btrfs_lockdep_release(fs_info, btrfs_trans_pending_ordered);
708
709 spin_lock(&root->ordered_extent_lock);
710 list_del_init(&entry->root_extent_list);
711 root->nr_ordered_extents--;
712
713 trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
714
715 if (!root->nr_ordered_extents) {
716 spin_lock(&fs_info->ordered_root_lock);
717 BUG_ON(list_empty(&root->ordered_root));
718 list_del_init(&root->ordered_root);
719 spin_unlock(&fs_info->ordered_root_lock);
720 }
721 spin_unlock(&root->ordered_extent_lock);
722 wake_up(&entry->wait);
723 if (!freespace_inode)
724 btrfs_lockdep_release(fs_info, btrfs_ordered_extent);
725}
726
727static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
728{
729 struct btrfs_ordered_extent *ordered;
730
731 ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
732 btrfs_start_ordered_extent(ordered);
733 complete(&ordered->completion);
734}
735
736/*
737 * Wait for all the ordered extents in a root. Use @bg as range or do whole
738 * range if it's NULL.
739 */
740u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
741 const struct btrfs_block_group *bg)
742{
743 struct btrfs_fs_info *fs_info = root->fs_info;
744 LIST_HEAD(splice);
745 LIST_HEAD(skipped);
746 LIST_HEAD(works);
747 struct btrfs_ordered_extent *ordered, *next;
748 u64 count = 0;
749 u64 range_start, range_len;
750 u64 range_end;
751
752 if (bg) {
753 range_start = bg->start;
754 range_len = bg->length;
755 } else {
756 range_start = 0;
757 range_len = U64_MAX;
758 }
759 range_end = range_start + range_len;
760
761 mutex_lock(&root->ordered_extent_mutex);
762 spin_lock(&root->ordered_extent_lock);
763 list_splice_init(&root->ordered_extents, &splice);
764 while (!list_empty(&splice) && nr) {
765 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
766 root_extent_list);
767
768 if (range_end <= ordered->disk_bytenr ||
769 ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
770 list_move_tail(&ordered->root_extent_list, &skipped);
771 cond_resched_lock(&root->ordered_extent_lock);
772 continue;
773 }
774
775 list_move_tail(&ordered->root_extent_list,
776 &root->ordered_extents);
777 refcount_inc(&ordered->refs);
778 spin_unlock(&root->ordered_extent_lock);
779
780 btrfs_init_work(&ordered->flush_work,
781 btrfs_run_ordered_extent_work, NULL);
782 list_add_tail(&ordered->work_list, &works);
783 btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
784
785 cond_resched();
786 if (nr != U64_MAX)
787 nr--;
788 count++;
789 spin_lock(&root->ordered_extent_lock);
790 }
791 list_splice_tail(&skipped, &root->ordered_extents);
792 list_splice_tail(&splice, &root->ordered_extents);
793 spin_unlock(&root->ordered_extent_lock);
794
795 list_for_each_entry_safe(ordered, next, &works, work_list) {
796 list_del_init(&ordered->work_list);
797 wait_for_completion(&ordered->completion);
798 btrfs_put_ordered_extent(ordered);
799 cond_resched();
800 }
801 mutex_unlock(&root->ordered_extent_mutex);
802
803 return count;
804}
805
806/*
807 * Wait for @nr ordered extents that intersect the @bg, or the whole range of
808 * the filesystem if @bg is NULL.
809 */
810void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
811 const struct btrfs_block_group *bg)
812{
813 struct btrfs_root *root;
814 LIST_HEAD(splice);
815 u64 done;
816
817 mutex_lock(&fs_info->ordered_operations_mutex);
818 spin_lock(&fs_info->ordered_root_lock);
819 list_splice_init(&fs_info->ordered_roots, &splice);
820 while (!list_empty(&splice) && nr) {
821 root = list_first_entry(&splice, struct btrfs_root,
822 ordered_root);
823 root = btrfs_grab_root(root);
824 BUG_ON(!root);
825 list_move_tail(&root->ordered_root,
826 &fs_info->ordered_roots);
827 spin_unlock(&fs_info->ordered_root_lock);
828
829 done = btrfs_wait_ordered_extents(root, nr, bg);
830 btrfs_put_root(root);
831
832 if (nr != U64_MAX)
833 nr -= done;
834
835 spin_lock(&fs_info->ordered_root_lock);
836 }
837 list_splice_tail(&splice, &fs_info->ordered_roots);
838 spin_unlock(&fs_info->ordered_root_lock);
839 mutex_unlock(&fs_info->ordered_operations_mutex);
840}
841
842/*
843 * Start IO and wait for a given ordered extent to finish.
844 *
845 * Wait on page writeback for all the pages in the extent and the IO completion
846 * code to insert metadata into the btree corresponding to the extent.
847 */
848void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry)
849{
850 u64 start = entry->file_offset;
851 u64 end = start + entry->num_bytes - 1;
852 struct btrfs_inode *inode = entry->inode;
853 bool freespace_inode;
854
855 trace_btrfs_ordered_extent_start(inode, entry);
856
857 /*
858 * If this is a free space inode do not take the ordered extents lockdep
859 * map.
860 */
861 freespace_inode = btrfs_is_free_space_inode(inode);
862
863 /*
864 * pages in the range can be dirty, clean or writeback. We
865 * start IO on any dirty ones so the wait doesn't stall waiting
866 * for the flusher thread to find them
867 */
868 if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
869 filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end);
870
871 if (!freespace_inode)
872 btrfs_might_wait_for_event(inode->root->fs_info, btrfs_ordered_extent);
873 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE, &entry->flags));
874}
875
876/*
877 * Used to wait on ordered extents across a large range of bytes.
878 */
879int btrfs_wait_ordered_range(struct btrfs_inode *inode, u64 start, u64 len)
880{
881 int ret = 0;
882 int ret_wb = 0;
883 u64 end;
884 u64 orig_end;
885 struct btrfs_ordered_extent *ordered;
886
887 if (start + len < start) {
888 orig_end = OFFSET_MAX;
889 } else {
890 orig_end = start + len - 1;
891 if (orig_end > OFFSET_MAX)
892 orig_end = OFFSET_MAX;
893 }
894
895 /* start IO across the range first to instantiate any delalloc
896 * extents
897 */
898 ret = btrfs_fdatawrite_range(inode, start, orig_end);
899 if (ret)
900 return ret;
901
902 /*
903 * If we have a writeback error don't return immediately. Wait first
904 * for any ordered extents that haven't completed yet. This is to make
905 * sure no one can dirty the same page ranges and call writepages()
906 * before the ordered extents complete - to avoid failures (-EEXIST)
907 * when adding the new ordered extents to the ordered tree.
908 */
909 ret_wb = filemap_fdatawait_range(inode->vfs_inode.i_mapping, start, orig_end);
910
911 end = orig_end;
912 while (1) {
913 ordered = btrfs_lookup_first_ordered_extent(inode, end);
914 if (!ordered)
915 break;
916 if (ordered->file_offset > orig_end) {
917 btrfs_put_ordered_extent(ordered);
918 break;
919 }
920 if (ordered->file_offset + ordered->num_bytes <= start) {
921 btrfs_put_ordered_extent(ordered);
922 break;
923 }
924 btrfs_start_ordered_extent(ordered);
925 end = ordered->file_offset;
926 /*
927 * If the ordered extent had an error save the error but don't
928 * exit without waiting first for all other ordered extents in
929 * the range to complete.
930 */
931 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
932 ret = -EIO;
933 btrfs_put_ordered_extent(ordered);
934 if (end == 0 || end == start)
935 break;
936 end--;
937 }
938 return ret_wb ? ret_wb : ret;
939}
940
941/*
942 * find an ordered extent corresponding to file_offset. return NULL if
943 * nothing is found, otherwise take a reference on the extent and return it
944 */
945struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
946 u64 file_offset)
947{
948 struct rb_node *node;
949 struct btrfs_ordered_extent *entry = NULL;
950 unsigned long flags;
951
952 spin_lock_irqsave(&inode->ordered_tree_lock, flags);
953 node = ordered_tree_search(inode, file_offset);
954 if (!node)
955 goto out;
956
957 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
958 if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
959 entry = NULL;
960 if (entry) {
961 refcount_inc(&entry->refs);
962 trace_btrfs_ordered_extent_lookup(inode, entry);
963 }
964out:
965 spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
966 return entry;
967}
968
969/* Since the DIO code tries to lock a wide area we need to look for any ordered
970 * extents that exist in the range, rather than just the start of the range.
971 */
972struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
973 struct btrfs_inode *inode, u64 file_offset, u64 len)
974{
975 struct rb_node *node;
976 struct btrfs_ordered_extent *entry = NULL;
977
978 spin_lock_irq(&inode->ordered_tree_lock);
979 node = ordered_tree_search(inode, file_offset);
980 if (!node) {
981 node = ordered_tree_search(inode, file_offset + len);
982 if (!node)
983 goto out;
984 }
985
986 while (1) {
987 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
988 if (btrfs_range_overlaps(entry, file_offset, len))
989 break;
990
991 if (entry->file_offset >= file_offset + len) {
992 entry = NULL;
993 break;
994 }
995 entry = NULL;
996 node = rb_next(node);
997 if (!node)
998 break;
999 }
1000out:
1001 if (entry) {
1002 refcount_inc(&entry->refs);
1003 trace_btrfs_ordered_extent_lookup_range(inode, entry);
1004 }
1005 spin_unlock_irq(&inode->ordered_tree_lock);
1006 return entry;
1007}
1008
1009/*
1010 * Adds all ordered extents to the given list. The list ends up sorted by the
1011 * file_offset of the ordered extents.
1012 */
1013void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
1014 struct list_head *list)
1015{
1016 struct rb_node *n;
1017
1018 btrfs_assert_inode_locked(inode);
1019
1020 spin_lock_irq(&inode->ordered_tree_lock);
1021 for (n = rb_first(&inode->ordered_tree); n; n = rb_next(n)) {
1022 struct btrfs_ordered_extent *ordered;
1023
1024 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
1025
1026 if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
1027 continue;
1028
1029 ASSERT(list_empty(&ordered->log_list));
1030 list_add_tail(&ordered->log_list, list);
1031 refcount_inc(&ordered->refs);
1032 trace_btrfs_ordered_extent_lookup_for_logging(inode, ordered);
1033 }
1034 spin_unlock_irq(&inode->ordered_tree_lock);
1035}
1036
1037/*
1038 * lookup and return any extent before 'file_offset'. NULL is returned
1039 * if none is found
1040 */
1041struct btrfs_ordered_extent *
1042btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset)
1043{
1044 struct rb_node *node;
1045 struct btrfs_ordered_extent *entry = NULL;
1046
1047 spin_lock_irq(&inode->ordered_tree_lock);
1048 node = ordered_tree_search(inode, file_offset);
1049 if (!node)
1050 goto out;
1051
1052 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
1053 refcount_inc(&entry->refs);
1054 trace_btrfs_ordered_extent_lookup_first(inode, entry);
1055out:
1056 spin_unlock_irq(&inode->ordered_tree_lock);
1057 return entry;
1058}
1059
1060/*
1061 * Lookup the first ordered extent that overlaps the range
1062 * [@file_offset, @file_offset + @len).
1063 *
1064 * The difference between this and btrfs_lookup_first_ordered_extent() is
1065 * that this one won't return any ordered extent that does not overlap the range.
1066 * And the difference against btrfs_lookup_ordered_extent() is, this function
1067 * ensures the first ordered extent gets returned.
1068 */
1069struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
1070 struct btrfs_inode *inode, u64 file_offset, u64 len)
1071{
1072 struct rb_node *node;
1073 struct rb_node *cur;
1074 struct rb_node *prev;
1075 struct rb_node *next;
1076 struct btrfs_ordered_extent *entry = NULL;
1077
1078 spin_lock_irq(&inode->ordered_tree_lock);
1079 node = inode->ordered_tree.rb_node;
1080 /*
1081 * Here we don't want to use tree_search() which will use tree->last
1082 * and screw up the search order.
1083 * And __tree_search() can't return the adjacent ordered extents
1084 * either, thus here we do our own search.
1085 */
1086 while (node) {
1087 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
1088
1089 if (file_offset < entry->file_offset) {
1090 node = node->rb_left;
1091 } else if (file_offset >= entry_end(entry)) {
1092 node = node->rb_right;
1093 } else {
1094 /*
1095 * Direct hit, got an ordered extent that starts at
1096 * @file_offset
1097 */
1098 goto out;
1099 }
1100 }
1101 if (!entry) {
1102 /* Empty tree */
1103 goto out;
1104 }
1105
1106 cur = &entry->rb_node;
1107 /* We got an entry around @file_offset, check adjacent entries */
1108 if (entry->file_offset < file_offset) {
1109 prev = cur;
1110 next = rb_next(cur);
1111 } else {
1112 prev = rb_prev(cur);
1113 next = cur;
1114 }
1115 if (prev) {
1116 entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
1117 if (btrfs_range_overlaps(entry, file_offset, len))
1118 goto out;
1119 }
1120 if (next) {
1121 entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
1122 if (btrfs_range_overlaps(entry, file_offset, len))
1123 goto out;
1124 }
1125 /* No ordered extent in the range */
1126 entry = NULL;
1127out:
1128 if (entry) {
1129 refcount_inc(&entry->refs);
1130 trace_btrfs_ordered_extent_lookup_first_range(inode, entry);
1131 }
1132
1133 spin_unlock_irq(&inode->ordered_tree_lock);
1134 return entry;
1135}
1136
1137/*
1138 * Lock the passed range and ensures all pending ordered extents in it are run
1139 * to completion.
1140 *
1141 * @inode: Inode whose ordered tree is to be searched
1142 * @start: Beginning of range to flush
1143 * @end: Last byte of range to lock
1144 * @cached_state: If passed, will return the extent state responsible for the
1145 * locked range. It's the caller's responsibility to free the
1146 * cached state.
1147 *
1148 * Always return with the given range locked, ensuring after it's called no
1149 * order extent can be pending.
1150 */
1151void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
1152 u64 end,
1153 struct extent_state **cached_state)
1154{
1155 struct btrfs_ordered_extent *ordered;
1156 struct extent_state *cache = NULL;
1157 struct extent_state **cachedp = &cache;
1158
1159 if (cached_state)
1160 cachedp = cached_state;
1161
1162 while (1) {
1163 lock_extent(&inode->io_tree, start, end, cachedp);
1164 ordered = btrfs_lookup_ordered_range(inode, start,
1165 end - start + 1);
1166 if (!ordered) {
1167 /*
1168 * If no external cached_state has been passed then
1169 * decrement the extra ref taken for cachedp since we
1170 * aren't exposing it outside of this function
1171 */
1172 if (!cached_state)
1173 refcount_dec(&cache->refs);
1174 break;
1175 }
1176 unlock_extent(&inode->io_tree, start, end, cachedp);
1177 btrfs_start_ordered_extent(ordered);
1178 btrfs_put_ordered_extent(ordered);
1179 }
1180}
1181
1182/*
1183 * Lock the passed range and ensure all pending ordered extents in it are run
1184 * to completion in nowait mode.
1185 *
1186 * Return true if btrfs_lock_ordered_range does not return any extents,
1187 * otherwise false.
1188 */
1189bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end,
1190 struct extent_state **cached_state)
1191{
1192 struct btrfs_ordered_extent *ordered;
1193
1194 if (!try_lock_extent(&inode->io_tree, start, end, cached_state))
1195 return false;
1196
1197 ordered = btrfs_lookup_ordered_range(inode, start, end - start + 1);
1198 if (!ordered)
1199 return true;
1200
1201 btrfs_put_ordered_extent(ordered);
1202 unlock_extent(&inode->io_tree, start, end, cached_state);
1203
1204 return false;
1205}
1206
1207/* Split out a new ordered extent for this first @len bytes of @ordered. */
1208struct btrfs_ordered_extent *btrfs_split_ordered_extent(
1209 struct btrfs_ordered_extent *ordered, u64 len)
1210{
1211 struct btrfs_inode *inode = ordered->inode;
1212 struct btrfs_root *root = inode->root;
1213 struct btrfs_fs_info *fs_info = root->fs_info;
1214 u64 file_offset = ordered->file_offset;
1215 u64 disk_bytenr = ordered->disk_bytenr;
1216 unsigned long flags = ordered->flags;
1217 struct btrfs_ordered_sum *sum, *tmpsum;
1218 struct btrfs_ordered_extent *new;
1219 struct rb_node *node;
1220 u64 offset = 0;
1221
1222 trace_btrfs_ordered_extent_split(inode, ordered);
1223
1224 ASSERT(!(flags & (1U << BTRFS_ORDERED_COMPRESSED)));
1225
1226 /*
1227 * The entire bio must be covered by the ordered extent, but we can't
1228 * reduce the original extent to a zero length either.
1229 */
1230 if (WARN_ON_ONCE(len >= ordered->num_bytes))
1231 return ERR_PTR(-EINVAL);
1232 /*
1233 * If our ordered extent had an error there's no point in continuing.
1234 * The error may have come from a transaction abort done either by this
1235 * task or some other concurrent task, and the transaction abort path
1236 * iterates over all existing ordered extents and sets the flag
1237 * BTRFS_ORDERED_IOERR on them.
1238 */
1239 if (unlikely(flags & (1U << BTRFS_ORDERED_IOERR))) {
1240 const int fs_error = BTRFS_FS_ERROR(fs_info);
1241
1242 return fs_error ? ERR_PTR(fs_error) : ERR_PTR(-EIO);
1243 }
1244 /* We cannot split partially completed ordered extents. */
1245 if (ordered->bytes_left) {
1246 ASSERT(!(flags & ~BTRFS_ORDERED_TYPE_FLAGS));
1247 if (WARN_ON_ONCE(ordered->bytes_left != ordered->disk_num_bytes))
1248 return ERR_PTR(-EINVAL);
1249 }
1250 /* We cannot split a compressed ordered extent. */
1251 if (WARN_ON_ONCE(ordered->disk_num_bytes != ordered->num_bytes))
1252 return ERR_PTR(-EINVAL);
1253
1254 new = alloc_ordered_extent(inode, file_offset, len, len, disk_bytenr,
1255 len, 0, flags, ordered->compress_type);
1256 if (IS_ERR(new))
1257 return new;
1258
1259 /* One ref for the tree. */
1260 refcount_inc(&new->refs);
1261
1262 /*
1263 * Take the root's ordered_extent_lock to avoid a race with
1264 * btrfs_wait_ordered_extents() when updating the disk_bytenr and
1265 * disk_num_bytes fields of the ordered extent below. And we disable
1266 * IRQs because the inode's ordered_tree_lock is used in IRQ context
1267 * elsewhere.
1268 *
1269 * There's no concern about a previous caller of
1270 * btrfs_wait_ordered_extents() getting the trimmed ordered extent
1271 * before we insert the new one, because even if it gets the ordered
1272 * extent before it's trimmed and the new one inserted, right before it
1273 * uses it or during its use, the ordered extent might have been
1274 * trimmed in the meanwhile, and it missed the new ordered extent.
1275 * There's no way around this and it's harmless for current use cases,
1276 * so we take the root's ordered_extent_lock to fix that race during
1277 * trimming and silence tools like KCSAN.
1278 */
1279 spin_lock_irq(&root->ordered_extent_lock);
1280 spin_lock(&inode->ordered_tree_lock);
1281
1282 /*
1283 * We don't have overlapping ordered extents (that would imply double
1284 * allocation of extents) and we checked above that the split length
1285 * does not cross the ordered extent's num_bytes field, so there's
1286 * no need to remove it and re-insert it in the tree.
1287 */
1288 ordered->file_offset += len;
1289 ordered->disk_bytenr += len;
1290 ordered->num_bytes -= len;
1291 ordered->disk_num_bytes -= len;
1292 ordered->ram_bytes -= len;
1293
1294 if (test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags)) {
1295 ASSERT(ordered->bytes_left == 0);
1296 new->bytes_left = 0;
1297 } else {
1298 ordered->bytes_left -= len;
1299 }
1300
1301 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags)) {
1302 if (ordered->truncated_len > len) {
1303 ordered->truncated_len -= len;
1304 } else {
1305 new->truncated_len = ordered->truncated_len;
1306 ordered->truncated_len = 0;
1307 }
1308 }
1309
1310 list_for_each_entry_safe(sum, tmpsum, &ordered->list, list) {
1311 if (offset == len)
1312 break;
1313 list_move_tail(&sum->list, &new->list);
1314 offset += sum->len;
1315 }
1316
1317 node = tree_insert(&inode->ordered_tree, new->file_offset, &new->rb_node);
1318 if (unlikely(node))
1319 btrfs_panic(fs_info, -EEXIST,
1320 "inconsistency in ordered tree at offset %llu after split",
1321 new->file_offset);
1322 spin_unlock(&inode->ordered_tree_lock);
1323
1324 list_add_tail(&new->root_extent_list, &root->ordered_extents);
1325 root->nr_ordered_extents++;
1326 spin_unlock_irq(&root->ordered_extent_lock);
1327 return new;
1328}
1329
1330int __init ordered_data_init(void)
1331{
1332 btrfs_ordered_extent_cache = KMEM_CACHE(btrfs_ordered_extent, 0);
1333 if (!btrfs_ordered_extent_cache)
1334 return -ENOMEM;
1335
1336 return 0;
1337}
1338
1339void __cold ordered_data_exit(void)
1340{
1341 kmem_cache_destroy(btrfs_ordered_extent_cache);
1342}