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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 "super.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 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 *tree_search(struct btrfs_ordered_inode_tree *tree,
128 u64 file_offset)
129{
130 struct rb_root *root = &tree->tree;
131 struct rb_node *prev = NULL;
132 struct rb_node *ret;
133 struct btrfs_ordered_extent *entry;
134
135 if (tree->last) {
136 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
137 rb_node);
138 if (in_range(file_offset, entry->file_offset, entry->num_bytes))
139 return tree->last;
140 }
141 ret = __tree_search(root, file_offset, &prev);
142 if (!ret)
143 ret = prev;
144 if (ret)
145 tree->last = ret;
146 return ret;
147}
148
149/*
150 * Add an ordered extent to the per-inode tree.
151 *
152 * @inode: Inode that this extent is for.
153 * @file_offset: Logical offset in file where the extent starts.
154 * @num_bytes: Logical length of extent in file.
155 * @ram_bytes: Full length of unencoded data.
156 * @disk_bytenr: Offset of extent on disk.
157 * @disk_num_bytes: Size of extent on disk.
158 * @offset: Offset into unencoded data where file data starts.
159 * @flags: Flags specifying type of extent (1 << BTRFS_ORDERED_*).
160 * @compress_type: Compression algorithm used for data.
161 *
162 * Most of these parameters correspond to &struct btrfs_file_extent_item. The
163 * tree is given a single reference on the ordered extent that was inserted.
164 *
165 * Return: 0 or -ENOMEM.
166 */
167int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
168 u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
169 u64 disk_num_bytes, u64 offset, unsigned flags,
170 int compress_type)
171{
172 struct btrfs_root *root = inode->root;
173 struct btrfs_fs_info *fs_info = root->fs_info;
174 struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
175 struct rb_node *node;
176 struct btrfs_ordered_extent *entry;
177 int ret;
178
179 if (flags &
180 ((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
181 /* For nocow write, we can release the qgroup rsv right now */
182 ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes);
183 if (ret < 0)
184 return ret;
185 ret = 0;
186 } else {
187 /*
188 * The ordered extent has reserved qgroup space, release now
189 * and pass the reserved number for qgroup_record to free.
190 */
191 ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes);
192 if (ret < 0)
193 return ret;
194 }
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->num_bytes = num_bytes;
201 entry->ram_bytes = ram_bytes;
202 entry->disk_bytenr = disk_bytenr;
203 entry->disk_num_bytes = disk_num_bytes;
204 entry->offset = offset;
205 entry->bytes_left = num_bytes;
206 entry->inode = igrab(&inode->vfs_inode);
207 entry->compress_type = compress_type;
208 entry->truncated_len = (u64)-1;
209 entry->qgroup_rsv = ret;
210 entry->physical = (u64)-1;
211
212 ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
213 entry->flags = flags;
214
215 percpu_counter_add_batch(&fs_info->ordered_bytes, num_bytes,
216 fs_info->delalloc_batch);
217
218 /* one ref for the tree */
219 refcount_set(&entry->refs, 1);
220 init_waitqueue_head(&entry->wait);
221 INIT_LIST_HEAD(&entry->list);
222 INIT_LIST_HEAD(&entry->log_list);
223 INIT_LIST_HEAD(&entry->root_extent_list);
224 INIT_LIST_HEAD(&entry->work_list);
225 init_completion(&entry->completion);
226
227 trace_btrfs_ordered_extent_add(inode, entry);
228
229 spin_lock_irq(&tree->lock);
230 node = tree_insert(&tree->tree, file_offset,
231 &entry->rb_node);
232 if (node)
233 btrfs_panic(fs_info, -EEXIST,
234 "inconsistency in ordered tree at offset %llu",
235 file_offset);
236 spin_unlock_irq(&tree->lock);
237
238 spin_lock(&root->ordered_extent_lock);
239 list_add_tail(&entry->root_extent_list,
240 &root->ordered_extents);
241 root->nr_ordered_extents++;
242 if (root->nr_ordered_extents == 1) {
243 spin_lock(&fs_info->ordered_root_lock);
244 BUG_ON(!list_empty(&root->ordered_root));
245 list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
246 spin_unlock(&fs_info->ordered_root_lock);
247 }
248 spin_unlock(&root->ordered_extent_lock);
249
250 /*
251 * We don't need the count_max_extents here, we can assume that all of
252 * that work has been done at higher layers, so this is truly the
253 * smallest the extent is going to get.
254 */
255 spin_lock(&inode->lock);
256 btrfs_mod_outstanding_extents(inode, 1);
257 spin_unlock(&inode->lock);
258
259 return 0;
260}
261
262/*
263 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
264 * when an ordered extent is finished. If the list covers more than one
265 * ordered extent, it is split across multiples.
266 */
267void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
268 struct btrfs_ordered_sum *sum)
269{
270 struct btrfs_ordered_inode_tree *tree;
271
272 tree = &BTRFS_I(entry->inode)->ordered_tree;
273 spin_lock_irq(&tree->lock);
274 list_add_tail(&sum->list, &entry->list);
275 spin_unlock_irq(&tree->lock);
276}
277
278static void finish_ordered_fn(struct btrfs_work *work)
279{
280 struct btrfs_ordered_extent *ordered_extent;
281
282 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
283 btrfs_finish_ordered_io(ordered_extent);
284}
285
286/*
287 * Mark all ordered extents io inside the specified range finished.
288 *
289 * @page: The involved page for the operation.
290 * For uncompressed buffered IO, the page status also needs to be
291 * updated to indicate whether the pending ordered io is finished.
292 * Can be NULL for direct IO and compressed write.
293 * For these cases, callers are ensured they won't execute the
294 * endio function twice.
295 *
296 * This function is called for endio, thus the range must have ordered
297 * extent(s) covering it.
298 */
299void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
300 struct page *page, u64 file_offset,
301 u64 num_bytes, bool uptodate)
302{
303 struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
304 struct btrfs_fs_info *fs_info = inode->root->fs_info;
305 struct btrfs_workqueue *wq;
306 struct rb_node *node;
307 struct btrfs_ordered_extent *entry = NULL;
308 unsigned long flags;
309 u64 cur = file_offset;
310
311 if (btrfs_is_free_space_inode(inode))
312 wq = fs_info->endio_freespace_worker;
313 else
314 wq = fs_info->endio_write_workers;
315
316 if (page)
317 ASSERT(page->mapping && page_offset(page) <= file_offset &&
318 file_offset + num_bytes <= page_offset(page) + PAGE_SIZE);
319
320 spin_lock_irqsave(&tree->lock, flags);
321 while (cur < file_offset + num_bytes) {
322 u64 entry_end;
323 u64 end;
324 u32 len;
325
326 node = tree_search(tree, cur);
327 /* No ordered extents at all */
328 if (!node)
329 break;
330
331 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
332 entry_end = entry->file_offset + entry->num_bytes;
333 /*
334 * |<-- OE --->| |
335 * cur
336 * Go to next OE.
337 */
338 if (cur >= entry_end) {
339 node = rb_next(node);
340 /* No more ordered extents, exit */
341 if (!node)
342 break;
343 entry = rb_entry(node, struct btrfs_ordered_extent,
344 rb_node);
345
346 /* Go to next ordered extent and continue */
347 cur = entry->file_offset;
348 continue;
349 }
350 /*
351 * | |<--- OE --->|
352 * cur
353 * Go to the start of OE.
354 */
355 if (cur < entry->file_offset) {
356 cur = entry->file_offset;
357 continue;
358 }
359
360 /*
361 * Now we are definitely inside one ordered extent.
362 *
363 * |<--- OE --->|
364 * |
365 * cur
366 */
367 end = min(entry->file_offset + entry->num_bytes,
368 file_offset + num_bytes) - 1;
369 ASSERT(end + 1 - cur < U32_MAX);
370 len = end + 1 - cur;
371
372 if (page) {
373 /*
374 * Ordered (Private2) bit indicates whether we still
375 * have pending io unfinished for the ordered extent.
376 *
377 * If there's no such bit, we need to skip to next range.
378 */
379 if (!btrfs_page_test_ordered(fs_info, page, cur, len)) {
380 cur += len;
381 continue;
382 }
383 btrfs_page_clear_ordered(fs_info, page, cur, len);
384 }
385
386 /* Now we're fine to update the accounting */
387 if (unlikely(len > entry->bytes_left)) {
388 WARN_ON(1);
389 btrfs_crit(fs_info,
390"bad ordered extent accounting, root=%llu ino=%llu OE offset=%llu OE len=%llu to_dec=%u left=%llu",
391 inode->root->root_key.objectid,
392 btrfs_ino(inode),
393 entry->file_offset,
394 entry->num_bytes,
395 len, entry->bytes_left);
396 entry->bytes_left = 0;
397 } else {
398 entry->bytes_left -= len;
399 }
400
401 if (!uptodate)
402 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
403
404 /*
405 * All the IO of the ordered extent is finished, we need to queue
406 * the finish_func to be executed.
407 */
408 if (entry->bytes_left == 0) {
409 set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
410 cond_wake_up(&entry->wait);
411 refcount_inc(&entry->refs);
412 trace_btrfs_ordered_extent_mark_finished(inode, entry);
413 spin_unlock_irqrestore(&tree->lock, flags);
414 btrfs_init_work(&entry->work, finish_ordered_fn, NULL, NULL);
415 btrfs_queue_work(wq, &entry->work);
416 spin_lock_irqsave(&tree->lock, flags);
417 }
418 cur += len;
419 }
420 spin_unlock_irqrestore(&tree->lock, flags);
421}
422
423/*
424 * Finish IO for one ordered extent across a given range. The range can only
425 * contain one ordered extent.
426 *
427 * @cached: The cached ordered extent. If not NULL, we can skip the tree
428 * search and use the ordered extent directly.
429 * Will be also used to store the finished ordered extent.
430 * @file_offset: File offset for the finished IO
431 * @io_size: Length of the finish IO range
432 *
433 * Return true if the ordered extent is finished in the range, and update
434 * @cached.
435 * Return false otherwise.
436 *
437 * NOTE: The range can NOT cross multiple ordered extents.
438 * Thus caller should ensure the range doesn't cross ordered extents.
439 */
440bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
441 struct btrfs_ordered_extent **cached,
442 u64 file_offset, u64 io_size)
443{
444 struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
445 struct rb_node *node;
446 struct btrfs_ordered_extent *entry = NULL;
447 unsigned long flags;
448 bool finished = false;
449
450 spin_lock_irqsave(&tree->lock, flags);
451 if (cached && *cached) {
452 entry = *cached;
453 goto have_entry;
454 }
455
456 node = tree_search(tree, file_offset);
457 if (!node)
458 goto out;
459
460 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
461have_entry:
462 if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
463 goto out;
464
465 if (io_size > entry->bytes_left)
466 btrfs_crit(inode->root->fs_info,
467 "bad ordered accounting left %llu size %llu",
468 entry->bytes_left, io_size);
469
470 entry->bytes_left -= io_size;
471
472 if (entry->bytes_left == 0) {
473 /*
474 * Ensure only one caller can set the flag and finished_ret
475 * accordingly
476 */
477 finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
478 /* test_and_set_bit implies a barrier */
479 cond_wake_up_nomb(&entry->wait);
480 }
481out:
482 if (finished && cached && entry) {
483 *cached = entry;
484 refcount_inc(&entry->refs);
485 trace_btrfs_ordered_extent_dec_test_pending(inode, entry);
486 }
487 spin_unlock_irqrestore(&tree->lock, flags);
488 return finished;
489}
490
491/*
492 * used to drop a reference on an ordered extent. This will free
493 * the extent if the last reference is dropped
494 */
495void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
496{
497 struct list_head *cur;
498 struct btrfs_ordered_sum *sum;
499
500 trace_btrfs_ordered_extent_put(BTRFS_I(entry->inode), entry);
501
502 if (refcount_dec_and_test(&entry->refs)) {
503 ASSERT(list_empty(&entry->root_extent_list));
504 ASSERT(list_empty(&entry->log_list));
505 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
506 if (entry->inode)
507 btrfs_add_delayed_iput(BTRFS_I(entry->inode));
508 while (!list_empty(&entry->list)) {
509 cur = entry->list.next;
510 sum = list_entry(cur, struct btrfs_ordered_sum, list);
511 list_del(&sum->list);
512 kvfree(sum);
513 }
514 kmem_cache_free(btrfs_ordered_extent_cache, entry);
515 }
516}
517
518/*
519 * remove an ordered extent from the tree. No references are dropped
520 * and waiters are woken up.
521 */
522void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
523 struct btrfs_ordered_extent *entry)
524{
525 struct btrfs_ordered_inode_tree *tree;
526 struct btrfs_root *root = btrfs_inode->root;
527 struct btrfs_fs_info *fs_info = root->fs_info;
528 struct rb_node *node;
529 bool pending;
530 bool freespace_inode;
531
532 /*
533 * If this is a free space inode the thread has not acquired the ordered
534 * extents lockdep map.
535 */
536 freespace_inode = btrfs_is_free_space_inode(btrfs_inode);
537
538 btrfs_lockdep_acquire(fs_info, btrfs_trans_pending_ordered);
539 /* This is paired with btrfs_add_ordered_extent. */
540 spin_lock(&btrfs_inode->lock);
541 btrfs_mod_outstanding_extents(btrfs_inode, -1);
542 spin_unlock(&btrfs_inode->lock);
543 if (root != fs_info->tree_root) {
544 u64 release;
545
546 if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
547 release = entry->disk_num_bytes;
548 else
549 release = entry->num_bytes;
550 btrfs_delalloc_release_metadata(btrfs_inode, release, false);
551 }
552
553 percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
554 fs_info->delalloc_batch);
555
556 tree = &btrfs_inode->ordered_tree;
557 spin_lock_irq(&tree->lock);
558 node = &entry->rb_node;
559 rb_erase(node, &tree->tree);
560 RB_CLEAR_NODE(node);
561 if (tree->last == node)
562 tree->last = NULL;
563 set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
564 pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
565 spin_unlock_irq(&tree->lock);
566
567 /*
568 * The current running transaction is waiting on us, we need to let it
569 * know that we're complete and wake it up.
570 */
571 if (pending) {
572 struct btrfs_transaction *trans;
573
574 /*
575 * The checks for trans are just a formality, it should be set,
576 * but if it isn't we don't want to deref/assert under the spin
577 * lock, so be nice and check if trans is set, but ASSERT() so
578 * if it isn't set a developer will notice.
579 */
580 spin_lock(&fs_info->trans_lock);
581 trans = fs_info->running_transaction;
582 if (trans)
583 refcount_inc(&trans->use_count);
584 spin_unlock(&fs_info->trans_lock);
585
586 ASSERT(trans);
587 if (trans) {
588 if (atomic_dec_and_test(&trans->pending_ordered))
589 wake_up(&trans->pending_wait);
590 btrfs_put_transaction(trans);
591 }
592 }
593
594 btrfs_lockdep_release(fs_info, btrfs_trans_pending_ordered);
595
596 spin_lock(&root->ordered_extent_lock);
597 list_del_init(&entry->root_extent_list);
598 root->nr_ordered_extents--;
599
600 trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
601
602 if (!root->nr_ordered_extents) {
603 spin_lock(&fs_info->ordered_root_lock);
604 BUG_ON(list_empty(&root->ordered_root));
605 list_del_init(&root->ordered_root);
606 spin_unlock(&fs_info->ordered_root_lock);
607 }
608 spin_unlock(&root->ordered_extent_lock);
609 wake_up(&entry->wait);
610 if (!freespace_inode)
611 btrfs_lockdep_release(fs_info, btrfs_ordered_extent);
612}
613
614static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
615{
616 struct btrfs_ordered_extent *ordered;
617
618 ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
619 btrfs_start_ordered_extent(ordered, 1);
620 complete(&ordered->completion);
621}
622
623/*
624 * wait for all the ordered extents in a root. This is done when balancing
625 * space between drives.
626 */
627u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
628 const u64 range_start, const u64 range_len)
629{
630 struct btrfs_fs_info *fs_info = root->fs_info;
631 LIST_HEAD(splice);
632 LIST_HEAD(skipped);
633 LIST_HEAD(works);
634 struct btrfs_ordered_extent *ordered, *next;
635 u64 count = 0;
636 const u64 range_end = range_start + range_len;
637
638 mutex_lock(&root->ordered_extent_mutex);
639 spin_lock(&root->ordered_extent_lock);
640 list_splice_init(&root->ordered_extents, &splice);
641 while (!list_empty(&splice) && nr) {
642 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
643 root_extent_list);
644
645 if (range_end <= ordered->disk_bytenr ||
646 ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
647 list_move_tail(&ordered->root_extent_list, &skipped);
648 cond_resched_lock(&root->ordered_extent_lock);
649 continue;
650 }
651
652 list_move_tail(&ordered->root_extent_list,
653 &root->ordered_extents);
654 refcount_inc(&ordered->refs);
655 spin_unlock(&root->ordered_extent_lock);
656
657 btrfs_init_work(&ordered->flush_work,
658 btrfs_run_ordered_extent_work, NULL, NULL);
659 list_add_tail(&ordered->work_list, &works);
660 btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
661
662 cond_resched();
663 spin_lock(&root->ordered_extent_lock);
664 if (nr != U64_MAX)
665 nr--;
666 count++;
667 }
668 list_splice_tail(&skipped, &root->ordered_extents);
669 list_splice_tail(&splice, &root->ordered_extents);
670 spin_unlock(&root->ordered_extent_lock);
671
672 list_for_each_entry_safe(ordered, next, &works, work_list) {
673 list_del_init(&ordered->work_list);
674 wait_for_completion(&ordered->completion);
675 btrfs_put_ordered_extent(ordered);
676 cond_resched();
677 }
678 mutex_unlock(&root->ordered_extent_mutex);
679
680 return count;
681}
682
683void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
684 const u64 range_start, const u64 range_len)
685{
686 struct btrfs_root *root;
687 struct list_head splice;
688 u64 done;
689
690 INIT_LIST_HEAD(&splice);
691
692 mutex_lock(&fs_info->ordered_operations_mutex);
693 spin_lock(&fs_info->ordered_root_lock);
694 list_splice_init(&fs_info->ordered_roots, &splice);
695 while (!list_empty(&splice) && nr) {
696 root = list_first_entry(&splice, struct btrfs_root,
697 ordered_root);
698 root = btrfs_grab_root(root);
699 BUG_ON(!root);
700 list_move_tail(&root->ordered_root,
701 &fs_info->ordered_roots);
702 spin_unlock(&fs_info->ordered_root_lock);
703
704 done = btrfs_wait_ordered_extents(root, nr,
705 range_start, range_len);
706 btrfs_put_root(root);
707
708 spin_lock(&fs_info->ordered_root_lock);
709 if (nr != U64_MAX) {
710 nr -= done;
711 }
712 }
713 list_splice_tail(&splice, &fs_info->ordered_roots);
714 spin_unlock(&fs_info->ordered_root_lock);
715 mutex_unlock(&fs_info->ordered_operations_mutex);
716}
717
718/*
719 * Used to start IO or wait for a given ordered extent to finish.
720 *
721 * If wait is one, this effectively waits on page writeback for all the pages
722 * in the extent, and it waits on the io completion code to insert
723 * metadata into the btree corresponding to the extent
724 */
725void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry, int wait)
726{
727 u64 start = entry->file_offset;
728 u64 end = start + entry->num_bytes - 1;
729 struct btrfs_inode *inode = BTRFS_I(entry->inode);
730 bool freespace_inode;
731
732 trace_btrfs_ordered_extent_start(inode, entry);
733
734 /*
735 * If this is a free space inode do not take the ordered extents lockdep
736 * map.
737 */
738 freespace_inode = btrfs_is_free_space_inode(inode);
739
740 /*
741 * pages in the range can be dirty, clean or writeback. We
742 * start IO on any dirty ones so the wait doesn't stall waiting
743 * for the flusher thread to find them
744 */
745 if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
746 filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end);
747 if (wait) {
748 if (!freespace_inode)
749 btrfs_might_wait_for_event(inode->root->fs_info, btrfs_ordered_extent);
750 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
751 &entry->flags));
752 }
753}
754
755/*
756 * Used to wait on ordered extents across a large range of bytes.
757 */
758int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
759{
760 int ret = 0;
761 int ret_wb = 0;
762 u64 end;
763 u64 orig_end;
764 struct btrfs_ordered_extent *ordered;
765
766 if (start + len < start) {
767 orig_end = OFFSET_MAX;
768 } else {
769 orig_end = start + len - 1;
770 if (orig_end > OFFSET_MAX)
771 orig_end = OFFSET_MAX;
772 }
773
774 /* start IO across the range first to instantiate any delalloc
775 * extents
776 */
777 ret = btrfs_fdatawrite_range(inode, start, orig_end);
778 if (ret)
779 return ret;
780
781 /*
782 * If we have a writeback error don't return immediately. Wait first
783 * for any ordered extents that haven't completed yet. This is to make
784 * sure no one can dirty the same page ranges and call writepages()
785 * before the ordered extents complete - to avoid failures (-EEXIST)
786 * when adding the new ordered extents to the ordered tree.
787 */
788 ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
789
790 end = orig_end;
791 while (1) {
792 ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode), end);
793 if (!ordered)
794 break;
795 if (ordered->file_offset > orig_end) {
796 btrfs_put_ordered_extent(ordered);
797 break;
798 }
799 if (ordered->file_offset + ordered->num_bytes <= start) {
800 btrfs_put_ordered_extent(ordered);
801 break;
802 }
803 btrfs_start_ordered_extent(ordered, 1);
804 end = ordered->file_offset;
805 /*
806 * If the ordered extent had an error save the error but don't
807 * exit without waiting first for all other ordered extents in
808 * the range to complete.
809 */
810 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
811 ret = -EIO;
812 btrfs_put_ordered_extent(ordered);
813 if (end == 0 || end == start)
814 break;
815 end--;
816 }
817 return ret_wb ? ret_wb : ret;
818}
819
820/*
821 * find an ordered extent corresponding to file_offset. return NULL if
822 * nothing is found, otherwise take a reference on the extent and return it
823 */
824struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
825 u64 file_offset)
826{
827 struct btrfs_ordered_inode_tree *tree;
828 struct rb_node *node;
829 struct btrfs_ordered_extent *entry = NULL;
830 unsigned long flags;
831
832 tree = &inode->ordered_tree;
833 spin_lock_irqsave(&tree->lock, flags);
834 node = tree_search(tree, file_offset);
835 if (!node)
836 goto out;
837
838 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
839 if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
840 entry = NULL;
841 if (entry) {
842 refcount_inc(&entry->refs);
843 trace_btrfs_ordered_extent_lookup(inode, entry);
844 }
845out:
846 spin_unlock_irqrestore(&tree->lock, flags);
847 return entry;
848}
849
850/* Since the DIO code tries to lock a wide area we need to look for any ordered
851 * extents that exist in the range, rather than just the start of the range.
852 */
853struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
854 struct btrfs_inode *inode, u64 file_offset, u64 len)
855{
856 struct btrfs_ordered_inode_tree *tree;
857 struct rb_node *node;
858 struct btrfs_ordered_extent *entry = NULL;
859
860 tree = &inode->ordered_tree;
861 spin_lock_irq(&tree->lock);
862 node = tree_search(tree, file_offset);
863 if (!node) {
864 node = tree_search(tree, file_offset + len);
865 if (!node)
866 goto out;
867 }
868
869 while (1) {
870 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
871 if (range_overlaps(entry, file_offset, len))
872 break;
873
874 if (entry->file_offset >= file_offset + len) {
875 entry = NULL;
876 break;
877 }
878 entry = NULL;
879 node = rb_next(node);
880 if (!node)
881 break;
882 }
883out:
884 if (entry) {
885 refcount_inc(&entry->refs);
886 trace_btrfs_ordered_extent_lookup_range(inode, entry);
887 }
888 spin_unlock_irq(&tree->lock);
889 return entry;
890}
891
892/*
893 * Adds all ordered extents to the given list. The list ends up sorted by the
894 * file_offset of the ordered extents.
895 */
896void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
897 struct list_head *list)
898{
899 struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
900 struct rb_node *n;
901
902 ASSERT(inode_is_locked(&inode->vfs_inode));
903
904 spin_lock_irq(&tree->lock);
905 for (n = rb_first(&tree->tree); n; n = rb_next(n)) {
906 struct btrfs_ordered_extent *ordered;
907
908 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
909
910 if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
911 continue;
912
913 ASSERT(list_empty(&ordered->log_list));
914 list_add_tail(&ordered->log_list, list);
915 refcount_inc(&ordered->refs);
916 trace_btrfs_ordered_extent_lookup_for_logging(inode, ordered);
917 }
918 spin_unlock_irq(&tree->lock);
919}
920
921/*
922 * lookup and return any extent before 'file_offset'. NULL is returned
923 * if none is found
924 */
925struct btrfs_ordered_extent *
926btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset)
927{
928 struct btrfs_ordered_inode_tree *tree;
929 struct rb_node *node;
930 struct btrfs_ordered_extent *entry = NULL;
931
932 tree = &inode->ordered_tree;
933 spin_lock_irq(&tree->lock);
934 node = tree_search(tree, file_offset);
935 if (!node)
936 goto out;
937
938 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
939 refcount_inc(&entry->refs);
940 trace_btrfs_ordered_extent_lookup_first(inode, entry);
941out:
942 spin_unlock_irq(&tree->lock);
943 return entry;
944}
945
946/*
947 * Lookup the first ordered extent that overlaps the range
948 * [@file_offset, @file_offset + @len).
949 *
950 * The difference between this and btrfs_lookup_first_ordered_extent() is
951 * that this one won't return any ordered extent that does not overlap the range.
952 * And the difference against btrfs_lookup_ordered_extent() is, this function
953 * ensures the first ordered extent gets returned.
954 */
955struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
956 struct btrfs_inode *inode, u64 file_offset, u64 len)
957{
958 struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
959 struct rb_node *node;
960 struct rb_node *cur;
961 struct rb_node *prev;
962 struct rb_node *next;
963 struct btrfs_ordered_extent *entry = NULL;
964
965 spin_lock_irq(&tree->lock);
966 node = tree->tree.rb_node;
967 /*
968 * Here we don't want to use tree_search() which will use tree->last
969 * and screw up the search order.
970 * And __tree_search() can't return the adjacent ordered extents
971 * either, thus here we do our own search.
972 */
973 while (node) {
974 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
975
976 if (file_offset < entry->file_offset) {
977 node = node->rb_left;
978 } else if (file_offset >= entry_end(entry)) {
979 node = node->rb_right;
980 } else {
981 /*
982 * Direct hit, got an ordered extent that starts at
983 * @file_offset
984 */
985 goto out;
986 }
987 }
988 if (!entry) {
989 /* Empty tree */
990 goto out;
991 }
992
993 cur = &entry->rb_node;
994 /* We got an entry around @file_offset, check adjacent entries */
995 if (entry->file_offset < file_offset) {
996 prev = cur;
997 next = rb_next(cur);
998 } else {
999 prev = rb_prev(cur);
1000 next = cur;
1001 }
1002 if (prev) {
1003 entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
1004 if (range_overlaps(entry, file_offset, len))
1005 goto out;
1006 }
1007 if (next) {
1008 entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
1009 if (range_overlaps(entry, file_offset, len))
1010 goto out;
1011 }
1012 /* No ordered extent in the range */
1013 entry = NULL;
1014out:
1015 if (entry) {
1016 refcount_inc(&entry->refs);
1017 trace_btrfs_ordered_extent_lookup_first_range(inode, entry);
1018 }
1019
1020 spin_unlock_irq(&tree->lock);
1021 return entry;
1022}
1023
1024/*
1025 * Lock the passed range and ensures all pending ordered extents in it are run
1026 * to completion.
1027 *
1028 * @inode: Inode whose ordered tree is to be searched
1029 * @start: Beginning of range to flush
1030 * @end: Last byte of range to lock
1031 * @cached_state: If passed, will return the extent state responsible for the
1032 * locked range. It's the caller's responsibility to free the
1033 * cached state.
1034 *
1035 * Always return with the given range locked, ensuring after it's called no
1036 * order extent can be pending.
1037 */
1038void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
1039 u64 end,
1040 struct extent_state **cached_state)
1041{
1042 struct btrfs_ordered_extent *ordered;
1043 struct extent_state *cache = NULL;
1044 struct extent_state **cachedp = &cache;
1045
1046 if (cached_state)
1047 cachedp = cached_state;
1048
1049 while (1) {
1050 lock_extent(&inode->io_tree, start, end, cachedp);
1051 ordered = btrfs_lookup_ordered_range(inode, start,
1052 end - start + 1);
1053 if (!ordered) {
1054 /*
1055 * If no external cached_state has been passed then
1056 * decrement the extra ref taken for cachedp since we
1057 * aren't exposing it outside of this function
1058 */
1059 if (!cached_state)
1060 refcount_dec(&cache->refs);
1061 break;
1062 }
1063 unlock_extent(&inode->io_tree, start, end, cachedp);
1064 btrfs_start_ordered_extent(ordered, 1);
1065 btrfs_put_ordered_extent(ordered);
1066 }
1067}
1068
1069/*
1070 * Lock the passed range and ensure all pending ordered extents in it are run
1071 * to completion in nowait mode.
1072 *
1073 * Return true if btrfs_lock_ordered_range does not return any extents,
1074 * otherwise false.
1075 */
1076bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end,
1077 struct extent_state **cached_state)
1078{
1079 struct btrfs_ordered_extent *ordered;
1080
1081 if (!try_lock_extent(&inode->io_tree, start, end, cached_state))
1082 return false;
1083
1084 ordered = btrfs_lookup_ordered_range(inode, start, end - start + 1);
1085 if (!ordered)
1086 return true;
1087
1088 btrfs_put_ordered_extent(ordered);
1089 unlock_extent(&inode->io_tree, start, end, cached_state);
1090
1091 return false;
1092}
1093
1094
1095static int clone_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pos,
1096 u64 len)
1097{
1098 struct inode *inode = ordered->inode;
1099 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
1100 u64 file_offset = ordered->file_offset + pos;
1101 u64 disk_bytenr = ordered->disk_bytenr + pos;
1102 unsigned long flags = ordered->flags & BTRFS_ORDERED_TYPE_FLAGS;
1103
1104 /*
1105 * The splitting extent is already counted and will be added again in
1106 * btrfs_add_ordered_extent_*(). Subtract len to avoid double counting.
1107 */
1108 percpu_counter_add_batch(&fs_info->ordered_bytes, -len,
1109 fs_info->delalloc_batch);
1110 WARN_ON_ONCE(flags & (1 << BTRFS_ORDERED_COMPRESSED));
1111 return btrfs_add_ordered_extent(BTRFS_I(inode), file_offset, len, len,
1112 disk_bytenr, len, 0, flags,
1113 ordered->compress_type);
1114}
1115
1116int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pre,
1117 u64 post)
1118{
1119 struct inode *inode = ordered->inode;
1120 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
1121 struct rb_node *node;
1122 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1123 int ret = 0;
1124
1125 trace_btrfs_ordered_extent_split(BTRFS_I(inode), ordered);
1126
1127 spin_lock_irq(&tree->lock);
1128 /* Remove from tree once */
1129 node = &ordered->rb_node;
1130 rb_erase(node, &tree->tree);
1131 RB_CLEAR_NODE(node);
1132 if (tree->last == node)
1133 tree->last = NULL;
1134
1135 ordered->file_offset += pre;
1136 ordered->disk_bytenr += pre;
1137 ordered->num_bytes -= (pre + post);
1138 ordered->disk_num_bytes -= (pre + post);
1139 ordered->bytes_left -= (pre + post);
1140
1141 /* Re-insert the node */
1142 node = tree_insert(&tree->tree, ordered->file_offset, &ordered->rb_node);
1143 if (node)
1144 btrfs_panic(fs_info, -EEXIST,
1145 "zoned: inconsistency in ordered tree at offset %llu",
1146 ordered->file_offset);
1147
1148 spin_unlock_irq(&tree->lock);
1149
1150 if (pre)
1151 ret = clone_ordered_extent(ordered, 0, pre);
1152 if (ret == 0 && post)
1153 ret = clone_ordered_extent(ordered, pre + ordered->disk_num_bytes,
1154 post);
1155
1156 return ret;
1157}
1158
1159int __init ordered_data_init(void)
1160{
1161 btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1162 sizeof(struct btrfs_ordered_extent), 0,
1163 SLAB_MEM_SPREAD,
1164 NULL);
1165 if (!btrfs_ordered_extent_cache)
1166 return -ENOMEM;
1167
1168 return 0;
1169}
1170
1171void __cold ordered_data_exit(void)
1172{
1173 kmem_cache_destroy(btrfs_ordered_extent_cache);
1174}
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
62static void ordered_data_tree_panic(struct inode *inode, int errno,
63 u64 offset)
64{
65 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
66 btrfs_panic(fs_info, errno, "Inconsistency in ordered tree at offset "
67 "%llu\n", (unsigned long long)offset);
68}
69
70/*
71 * look for a given offset in the tree, and if it can't be found return the
72 * first lesser offset
73 */
74static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
75 struct rb_node **prev_ret)
76{
77 struct rb_node *n = root->rb_node;
78 struct rb_node *prev = NULL;
79 struct rb_node *test;
80 struct btrfs_ordered_extent *entry;
81 struct btrfs_ordered_extent *prev_entry = NULL;
82
83 while (n) {
84 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
85 prev = n;
86 prev_entry = entry;
87
88 if (file_offset < entry->file_offset)
89 n = n->rb_left;
90 else if (file_offset >= entry_end(entry))
91 n = n->rb_right;
92 else
93 return n;
94 }
95 if (!prev_ret)
96 return NULL;
97
98 while (prev && file_offset >= entry_end(prev_entry)) {
99 test = rb_next(prev);
100 if (!test)
101 break;
102 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
103 rb_node);
104 if (file_offset < entry_end(prev_entry))
105 break;
106
107 prev = test;
108 }
109 if (prev)
110 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
111 rb_node);
112 while (prev && file_offset < entry_end(prev_entry)) {
113 test = rb_prev(prev);
114 if (!test)
115 break;
116 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
117 rb_node);
118 prev = test;
119 }
120 *prev_ret = prev;
121 return NULL;
122}
123
124/*
125 * helper to check if a given offset is inside a given entry
126 */
127static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
128{
129 if (file_offset < entry->file_offset ||
130 entry->file_offset + entry->len <= file_offset)
131 return 0;
132 return 1;
133}
134
135static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
136 u64 len)
137{
138 if (file_offset + len <= entry->file_offset ||
139 entry->file_offset + entry->len <= file_offset)
140 return 0;
141 return 1;
142}
143
144/*
145 * look find the first ordered struct that has this offset, otherwise
146 * the first one less than this offset
147 */
148static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
149 u64 file_offset)
150{
151 struct rb_root *root = &tree->tree;
152 struct rb_node *prev = NULL;
153 struct rb_node *ret;
154 struct btrfs_ordered_extent *entry;
155
156 if (tree->last) {
157 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
158 rb_node);
159 if (offset_in_entry(entry, file_offset))
160 return tree->last;
161 }
162 ret = __tree_search(root, file_offset, &prev);
163 if (!ret)
164 ret = prev;
165 if (ret)
166 tree->last = ret;
167 return ret;
168}
169
170/* allocate and add a new ordered_extent into the per-inode tree.
171 * file_offset is the logical offset in the file
172 *
173 * start is the disk block number of an extent already reserved in the
174 * extent allocation tree
175 *
176 * len is the length of the extent
177 *
178 * The tree is given a single reference on the ordered extent that was
179 * inserted.
180 */
181static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
182 u64 start, u64 len, u64 disk_len,
183 int type, int dio, int compress_type)
184{
185 struct btrfs_ordered_inode_tree *tree;
186 struct rb_node *node;
187 struct btrfs_ordered_extent *entry;
188
189 tree = &BTRFS_I(inode)->ordered_tree;
190 entry = kzalloc(sizeof(*entry), GFP_NOFS);
191 if (!entry)
192 return -ENOMEM;
193
194 entry->file_offset = file_offset;
195 entry->start = start;
196 entry->len = len;
197 entry->disk_len = disk_len;
198 entry->bytes_left = len;
199 entry->inode = igrab(inode);
200 entry->compress_type = compress_type;
201 if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
202 set_bit(type, &entry->flags);
203
204 if (dio)
205 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
206
207 /* one ref for the tree */
208 atomic_set(&entry->refs, 1);
209 init_waitqueue_head(&entry->wait);
210 INIT_LIST_HEAD(&entry->list);
211 INIT_LIST_HEAD(&entry->root_extent_list);
212
213 trace_btrfs_ordered_extent_add(inode, entry);
214
215 spin_lock_irq(&tree->lock);
216 node = tree_insert(&tree->tree, file_offset,
217 &entry->rb_node);
218 if (node)
219 ordered_data_tree_panic(inode, -EEXIST, file_offset);
220 spin_unlock_irq(&tree->lock);
221
222 spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
223 list_add_tail(&entry->root_extent_list,
224 &BTRFS_I(inode)->root->fs_info->ordered_extents);
225 spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
226
227 return 0;
228}
229
230int btrfs_add_ordered_extent(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, 0,
235 BTRFS_COMPRESS_NONE);
236}
237
238int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
239 u64 start, u64 len, u64 disk_len, int type)
240{
241 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
242 disk_len, type, 1,
243 BTRFS_COMPRESS_NONE);
244}
245
246int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
247 u64 start, u64 len, u64 disk_len,
248 int type, int compress_type)
249{
250 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
251 disk_len, type, 0,
252 compress_type);
253}
254
255/*
256 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
257 * when an ordered extent is finished. If the list covers more than one
258 * ordered extent, it is split across multiples.
259 */
260void btrfs_add_ordered_sum(struct inode *inode,
261 struct btrfs_ordered_extent *entry,
262 struct btrfs_ordered_sum *sum)
263{
264 struct btrfs_ordered_inode_tree *tree;
265
266 tree = &BTRFS_I(inode)->ordered_tree;
267 spin_lock_irq(&tree->lock);
268 list_add_tail(&sum->list, &entry->list);
269 spin_unlock_irq(&tree->lock);
270}
271
272/*
273 * this is used to account for finished IO across a given range
274 * of the file. The IO may span ordered extents. If
275 * a given ordered_extent is completely done, 1 is returned, otherwise
276 * 0.
277 *
278 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
279 * to make sure this function only returns 1 once for a given ordered extent.
280 *
281 * file_offset is updated to one byte past the range that is recorded as
282 * complete. This allows you to walk forward in the file.
283 */
284int btrfs_dec_test_first_ordered_pending(struct inode *inode,
285 struct btrfs_ordered_extent **cached,
286 u64 *file_offset, u64 io_size, int uptodate)
287{
288 struct btrfs_ordered_inode_tree *tree;
289 struct rb_node *node;
290 struct btrfs_ordered_extent *entry = NULL;
291 int ret;
292 unsigned long flags;
293 u64 dec_end;
294 u64 dec_start;
295 u64 to_dec;
296
297 tree = &BTRFS_I(inode)->ordered_tree;
298 spin_lock_irqsave(&tree->lock, flags);
299 node = tree_search(tree, *file_offset);
300 if (!node) {
301 ret = 1;
302 goto out;
303 }
304
305 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
306 if (!offset_in_entry(entry, *file_offset)) {
307 ret = 1;
308 goto out;
309 }
310
311 dec_start = max(*file_offset, entry->file_offset);
312 dec_end = min(*file_offset + io_size, entry->file_offset +
313 entry->len);
314 *file_offset = dec_end;
315 if (dec_start > dec_end) {
316 printk(KERN_CRIT "bad ordering dec_start %llu end %llu\n",
317 (unsigned long long)dec_start,
318 (unsigned long long)dec_end);
319 }
320 to_dec = dec_end - dec_start;
321 if (to_dec > entry->bytes_left) {
322 printk(KERN_CRIT "bad ordered accounting left %llu size %llu\n",
323 (unsigned long long)entry->bytes_left,
324 (unsigned long long)to_dec);
325 }
326 entry->bytes_left -= to_dec;
327 if (!uptodate)
328 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
329
330 if (entry->bytes_left == 0)
331 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
332 else
333 ret = 1;
334out:
335 if (!ret && cached && entry) {
336 *cached = entry;
337 atomic_inc(&entry->refs);
338 }
339 spin_unlock_irqrestore(&tree->lock, flags);
340 return ret == 0;
341}
342
343/*
344 * this is used to account for finished IO across a given range
345 * of the file. The IO should not span ordered extents. If
346 * a given ordered_extent is completely done, 1 is returned, otherwise
347 * 0.
348 *
349 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
350 * to make sure this function only returns 1 once for a given ordered extent.
351 */
352int btrfs_dec_test_ordered_pending(struct inode *inode,
353 struct btrfs_ordered_extent **cached,
354 u64 file_offset, u64 io_size, int uptodate)
355{
356 struct btrfs_ordered_inode_tree *tree;
357 struct rb_node *node;
358 struct btrfs_ordered_extent *entry = NULL;
359 unsigned long flags;
360 int ret;
361
362 tree = &BTRFS_I(inode)->ordered_tree;
363 spin_lock_irqsave(&tree->lock, flags);
364 if (cached && *cached) {
365 entry = *cached;
366 goto have_entry;
367 }
368
369 node = tree_search(tree, file_offset);
370 if (!node) {
371 ret = 1;
372 goto out;
373 }
374
375 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
376have_entry:
377 if (!offset_in_entry(entry, file_offset)) {
378 ret = 1;
379 goto out;
380 }
381
382 if (io_size > entry->bytes_left) {
383 printk(KERN_CRIT "bad ordered accounting left %llu size %llu\n",
384 (unsigned long long)entry->bytes_left,
385 (unsigned long long)io_size);
386 }
387 entry->bytes_left -= io_size;
388 if (!uptodate)
389 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
390
391 if (entry->bytes_left == 0)
392 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
393 else
394 ret = 1;
395out:
396 if (!ret && cached && entry) {
397 *cached = entry;
398 atomic_inc(&entry->refs);
399 }
400 spin_unlock_irqrestore(&tree->lock, flags);
401 return ret == 0;
402}
403
404/*
405 * used to drop a reference on an ordered extent. This will free
406 * the extent if the last reference is dropped
407 */
408void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
409{
410 struct list_head *cur;
411 struct btrfs_ordered_sum *sum;
412
413 trace_btrfs_ordered_extent_put(entry->inode, entry);
414
415 if (atomic_dec_and_test(&entry->refs)) {
416 if (entry->inode)
417 btrfs_add_delayed_iput(entry->inode);
418 while (!list_empty(&entry->list)) {
419 cur = entry->list.next;
420 sum = list_entry(cur, struct btrfs_ordered_sum, list);
421 list_del(&sum->list);
422 kfree(sum);
423 }
424 kfree(entry);
425 }
426}
427
428/*
429 * remove an ordered extent from the tree. No references are dropped
430 * and waiters are woken up.
431 */
432void btrfs_remove_ordered_extent(struct inode *inode,
433 struct btrfs_ordered_extent *entry)
434{
435 struct btrfs_ordered_inode_tree *tree;
436 struct btrfs_root *root = BTRFS_I(inode)->root;
437 struct rb_node *node;
438
439 tree = &BTRFS_I(inode)->ordered_tree;
440 spin_lock_irq(&tree->lock);
441 node = &entry->rb_node;
442 rb_erase(node, &tree->tree);
443 tree->last = NULL;
444 set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
445 spin_unlock_irq(&tree->lock);
446
447 spin_lock(&root->fs_info->ordered_extent_lock);
448 list_del_init(&entry->root_extent_list);
449
450 trace_btrfs_ordered_extent_remove(inode, entry);
451
452 /*
453 * we have no more ordered extents for this inode and
454 * no dirty pages. We can safely remove it from the
455 * list of ordered extents
456 */
457 if (RB_EMPTY_ROOT(&tree->tree) &&
458 !mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY)) {
459 list_del_init(&BTRFS_I(inode)->ordered_operations);
460 }
461 spin_unlock(&root->fs_info->ordered_extent_lock);
462 wake_up(&entry->wait);
463}
464
465/*
466 * wait for all the ordered extents in a root. This is done when balancing
467 * space between drives.
468 */
469void btrfs_wait_ordered_extents(struct btrfs_root *root,
470 int nocow_only, int delay_iput)
471{
472 struct list_head splice;
473 struct list_head *cur;
474 struct btrfs_ordered_extent *ordered;
475 struct inode *inode;
476
477 INIT_LIST_HEAD(&splice);
478
479 spin_lock(&root->fs_info->ordered_extent_lock);
480 list_splice_init(&root->fs_info->ordered_extents, &splice);
481 while (!list_empty(&splice)) {
482 cur = splice.next;
483 ordered = list_entry(cur, struct btrfs_ordered_extent,
484 root_extent_list);
485 if (nocow_only &&
486 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags) &&
487 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) {
488 list_move(&ordered->root_extent_list,
489 &root->fs_info->ordered_extents);
490 cond_resched_lock(&root->fs_info->ordered_extent_lock);
491 continue;
492 }
493
494 list_del_init(&ordered->root_extent_list);
495 atomic_inc(&ordered->refs);
496
497 /*
498 * the inode may be getting freed (in sys_unlink path).
499 */
500 inode = igrab(ordered->inode);
501
502 spin_unlock(&root->fs_info->ordered_extent_lock);
503
504 if (inode) {
505 btrfs_start_ordered_extent(inode, ordered, 1);
506 btrfs_put_ordered_extent(ordered);
507 if (delay_iput)
508 btrfs_add_delayed_iput(inode);
509 else
510 iput(inode);
511 } else {
512 btrfs_put_ordered_extent(ordered);
513 }
514
515 spin_lock(&root->fs_info->ordered_extent_lock);
516 }
517 spin_unlock(&root->fs_info->ordered_extent_lock);
518}
519
520/*
521 * this is used during transaction commit to write all the inodes
522 * added to the ordered operation list. These files must be fully on
523 * disk before the transaction commits.
524 *
525 * we have two modes here, one is to just start the IO via filemap_flush
526 * and the other is to wait for all the io. When we wait, we have an
527 * extra check to make sure the ordered operation list really is empty
528 * before we return
529 */
530void btrfs_run_ordered_operations(struct btrfs_root *root, int wait)
531{
532 struct btrfs_inode *btrfs_inode;
533 struct inode *inode;
534 struct list_head splice;
535
536 INIT_LIST_HEAD(&splice);
537
538 mutex_lock(&root->fs_info->ordered_operations_mutex);
539 spin_lock(&root->fs_info->ordered_extent_lock);
540again:
541 list_splice_init(&root->fs_info->ordered_operations, &splice);
542
543 while (!list_empty(&splice)) {
544 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
545 ordered_operations);
546
547 inode = &btrfs_inode->vfs_inode;
548
549 list_del_init(&btrfs_inode->ordered_operations);
550
551 /*
552 * the inode may be getting freed (in sys_unlink path).
553 */
554 inode = igrab(inode);
555
556 if (!wait && inode) {
557 list_add_tail(&BTRFS_I(inode)->ordered_operations,
558 &root->fs_info->ordered_operations);
559 }
560 spin_unlock(&root->fs_info->ordered_extent_lock);
561
562 if (inode) {
563 if (wait)
564 btrfs_wait_ordered_range(inode, 0, (u64)-1);
565 else
566 filemap_flush(inode->i_mapping);
567 btrfs_add_delayed_iput(inode);
568 }
569
570 cond_resched();
571 spin_lock(&root->fs_info->ordered_extent_lock);
572 }
573 if (wait && !list_empty(&root->fs_info->ordered_operations))
574 goto again;
575
576 spin_unlock(&root->fs_info->ordered_extent_lock);
577 mutex_unlock(&root->fs_info->ordered_operations_mutex);
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 */
612void 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 }
626
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 /*
633 * So with compression we will find and lock a dirty page and clear the
634 * first one as dirty, setup an async extent, and immediately return
635 * with the entire range locked but with nobody actually marked with
636 * writeback. So we can't just filemap_write_and_wait_range() and
637 * expect it to work since it will just kick off a thread to do the
638 * actual work. So we need to call filemap_fdatawrite_range _again_
639 * since it will wait on the page lock, which won't be unlocked until
640 * after the pages have been marked as writeback and so we're good to go
641 * from there. We have to do this otherwise we'll miss the ordered
642 * extents and that results in badness. Please Josef, do not think you
643 * know better and pull this out at some point in the future, it is
644 * right and you are wrong.
645 */
646 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
647 &BTRFS_I(inode)->runtime_flags))
648 filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
649
650 filemap_fdatawait_range(inode->i_mapping, start, orig_end);
651
652 end = orig_end;
653 found = 0;
654 while (1) {
655 ordered = btrfs_lookup_first_ordered_extent(inode, end);
656 if (!ordered)
657 break;
658 if (ordered->file_offset > orig_end) {
659 btrfs_put_ordered_extent(ordered);
660 break;
661 }
662 if (ordered->file_offset + ordered->len < start) {
663 btrfs_put_ordered_extent(ordered);
664 break;
665 }
666 found++;
667 btrfs_start_ordered_extent(inode, ordered, 1);
668 end = ordered->file_offset;
669 btrfs_put_ordered_extent(ordered);
670 if (end == 0 || end == start)
671 break;
672 end--;
673 }
674}
675
676/*
677 * find an ordered extent corresponding to file_offset. return NULL if
678 * nothing is found, otherwise take a reference on the extent and return it
679 */
680struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
681 u64 file_offset)
682{
683 struct btrfs_ordered_inode_tree *tree;
684 struct rb_node *node;
685 struct btrfs_ordered_extent *entry = NULL;
686
687 tree = &BTRFS_I(inode)->ordered_tree;
688 spin_lock_irq(&tree->lock);
689 node = tree_search(tree, file_offset);
690 if (!node)
691 goto out;
692
693 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
694 if (!offset_in_entry(entry, file_offset))
695 entry = NULL;
696 if (entry)
697 atomic_inc(&entry->refs);
698out:
699 spin_unlock_irq(&tree->lock);
700 return entry;
701}
702
703/* Since the DIO code tries to lock a wide area we need to look for any ordered
704 * extents that exist in the range, rather than just the start of the range.
705 */
706struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
707 u64 file_offset,
708 u64 len)
709{
710 struct btrfs_ordered_inode_tree *tree;
711 struct rb_node *node;
712 struct btrfs_ordered_extent *entry = NULL;
713
714 tree = &BTRFS_I(inode)->ordered_tree;
715 spin_lock_irq(&tree->lock);
716 node = tree_search(tree, file_offset);
717 if (!node) {
718 node = tree_search(tree, file_offset + len);
719 if (!node)
720 goto out;
721 }
722
723 while (1) {
724 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
725 if (range_overlaps(entry, file_offset, len))
726 break;
727
728 if (entry->file_offset >= file_offset + len) {
729 entry = NULL;
730 break;
731 }
732 entry = NULL;
733 node = rb_next(node);
734 if (!node)
735 break;
736 }
737out:
738 if (entry)
739 atomic_inc(&entry->refs);
740 spin_unlock_irq(&tree->lock);
741 return entry;
742}
743
744/*
745 * lookup and return any extent before 'file_offset'. NULL is returned
746 * if none is found
747 */
748struct btrfs_ordered_extent *
749btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
750{
751 struct btrfs_ordered_inode_tree *tree;
752 struct rb_node *node;
753 struct btrfs_ordered_extent *entry = NULL;
754
755 tree = &BTRFS_I(inode)->ordered_tree;
756 spin_lock_irq(&tree->lock);
757 node = tree_search(tree, file_offset);
758 if (!node)
759 goto out;
760
761 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
762 atomic_inc(&entry->refs);
763out:
764 spin_unlock_irq(&tree->lock);
765 return entry;
766}
767
768/*
769 * After an extent is done, call this to conditionally update the on disk
770 * i_size. i_size is updated to cover any fully written part of the file.
771 */
772int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
773 struct btrfs_ordered_extent *ordered)
774{
775 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
776 u64 disk_i_size;
777 u64 new_i_size;
778 u64 i_size_test;
779 u64 i_size = i_size_read(inode);
780 struct rb_node *node;
781 struct rb_node *prev = NULL;
782 struct btrfs_ordered_extent *test;
783 int ret = 1;
784
785 if (ordered)
786 offset = entry_end(ordered);
787 else
788 offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize);
789
790 spin_lock_irq(&tree->lock);
791 disk_i_size = BTRFS_I(inode)->disk_i_size;
792
793 /* truncate file */
794 if (disk_i_size > i_size) {
795 BTRFS_I(inode)->disk_i_size = i_size;
796 ret = 0;
797 goto out;
798 }
799
800 /*
801 * if the disk i_size is already at the inode->i_size, or
802 * this ordered extent is inside the disk i_size, we're done
803 */
804 if (disk_i_size == i_size || offset <= disk_i_size) {
805 goto out;
806 }
807
808 /*
809 * walk backward from this ordered extent to disk_i_size.
810 * if we find an ordered extent then we can't update disk i_size
811 * yet
812 */
813 if (ordered) {
814 node = rb_prev(&ordered->rb_node);
815 } else {
816 prev = tree_search(tree, offset);
817 /*
818 * we insert file extents without involving ordered struct,
819 * so there should be no ordered struct cover this offset
820 */
821 if (prev) {
822 test = rb_entry(prev, struct btrfs_ordered_extent,
823 rb_node);
824 BUG_ON(offset_in_entry(test, offset));
825 }
826 node = prev;
827 }
828 for (; node; node = rb_prev(node)) {
829 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
830
831 /* We treat this entry as if it doesnt exist */
832 if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
833 continue;
834 if (test->file_offset + test->len <= disk_i_size)
835 break;
836 if (test->file_offset >= i_size)
837 break;
838 if (test->file_offset >= disk_i_size)
839 goto out;
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
858 /*
859 * We are looking for an area between our current extent and the next
860 * ordered extent to update the i_size to. There are 3 cases here
861 *
862 * 1) We don't actually have anything and we can update to i_size.
863 * 2) We have stuff but they already did their i_size update so again we
864 * can just update to i_size.
865 * 3) We have an outstanding ordered extent so the most we can update
866 * our disk_i_size to is the start of the next offset.
867 */
868 i_size_test = i_size;
869 for (; node; node = rb_next(node)) {
870 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
871
872 if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
873 continue;
874 if (test->file_offset > offset) {
875 i_size_test = test->file_offset;
876 break;
877 }
878 }
879
880 /*
881 * i_size_test is the end of a region after this ordered
882 * extent where there are no ordered extents, we can safely set
883 * disk_i_size to this.
884 */
885 if (i_size_test > offset)
886 new_i_size = min_t(u64, i_size_test, i_size);
887 BTRFS_I(inode)->disk_i_size = new_i_size;
888 ret = 0;
889out:
890 /*
891 * We need to do this because we can't remove ordered extents until
892 * after the i_disk_size has been updated and then the inode has been
893 * updated to reflect the change, so we need to tell anybody who finds
894 * this ordered extent that we've already done all the real work, we
895 * just haven't completed all the other work.
896 */
897 if (ordered)
898 set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
899 spin_unlock_irq(&tree->lock);
900 return ret;
901}
902
903/*
904 * search the ordered extents for one corresponding to 'offset' and
905 * try to find a checksum. This is used because we allow pages to
906 * be reclaimed before their checksum is actually put into the btree
907 */
908int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
909 u32 *sum)
910{
911 struct btrfs_ordered_sum *ordered_sum;
912 struct btrfs_sector_sum *sector_sums;
913 struct btrfs_ordered_extent *ordered;
914 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
915 unsigned long num_sectors;
916 unsigned long i;
917 u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
918 int ret = 1;
919
920 ordered = btrfs_lookup_ordered_extent(inode, offset);
921 if (!ordered)
922 return 1;
923
924 spin_lock_irq(&tree->lock);
925 list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
926 if (disk_bytenr >= ordered_sum->bytenr) {
927 num_sectors = ordered_sum->len / sectorsize;
928 sector_sums = ordered_sum->sums;
929 for (i = 0; i < num_sectors; i++) {
930 if (sector_sums[i].bytenr == disk_bytenr) {
931 *sum = sector_sums[i].sum;
932 ret = 0;
933 goto out;
934 }
935 }
936 }
937 }
938out:
939 spin_unlock_irq(&tree->lock);
940 btrfs_put_ordered_extent(ordered);
941 return ret;
942}
943
944
945/*
946 * add a given inode to the list of inodes that must be fully on
947 * disk before a transaction commit finishes.
948 *
949 * This basically gives us the ext3 style data=ordered mode, and it is mostly
950 * used to make sure renamed files are fully on disk.
951 *
952 * It is a noop if the inode is already fully on disk.
953 *
954 * If trans is not null, we'll do a friendly check for a transaction that
955 * is already flushing things and force the IO down ourselves.
956 */
957void btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
958 struct btrfs_root *root, struct inode *inode)
959{
960 u64 last_mod;
961
962 last_mod = max(BTRFS_I(inode)->generation, BTRFS_I(inode)->last_trans);
963
964 /*
965 * if this file hasn't been changed since the last transaction
966 * commit, we can safely return without doing anything
967 */
968 if (last_mod < root->fs_info->last_trans_committed)
969 return;
970
971 /*
972 * the transaction is already committing. Just start the IO and
973 * don't bother with all of this list nonsense
974 */
975 if (trans && root->fs_info->running_transaction->blocked) {
976 btrfs_wait_ordered_range(inode, 0, (u64)-1);
977 return;
978 }
979
980 spin_lock(&root->fs_info->ordered_extent_lock);
981 if (list_empty(&BTRFS_I(inode)->ordered_operations)) {
982 list_add_tail(&BTRFS_I(inode)->ordered_operations,
983 &root->fs_info->ordered_operations);
984 }
985 spin_unlock(&root->fs_info->ordered_extent_lock);
986}