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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2009 Oracle. All rights reserved.
4 */
5
6#include <linux/sched.h>
7#include <linux/slab.h>
8#include <linux/sort.h>
9#include "ctree.h"
10#include "delayed-ref.h"
11#include "transaction.h"
12#include "qgroup.h"
13#include "space-info.h"
14
15struct kmem_cache *btrfs_delayed_ref_head_cachep;
16struct kmem_cache *btrfs_delayed_tree_ref_cachep;
17struct kmem_cache *btrfs_delayed_data_ref_cachep;
18struct kmem_cache *btrfs_delayed_extent_op_cachep;
19/*
20 * delayed back reference update tracking. For subvolume trees
21 * we queue up extent allocations and backref maintenance for
22 * delayed processing. This avoids deep call chains where we
23 * add extents in the middle of btrfs_search_slot, and it allows
24 * us to buffer up frequently modified backrefs in an rb tree instead
25 * of hammering updates on the extent allocation tree.
26 */
27
28bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info)
29{
30 struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
31 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
32 bool ret = false;
33 u64 reserved;
34
35 spin_lock(&global_rsv->lock);
36 reserved = global_rsv->reserved;
37 spin_unlock(&global_rsv->lock);
38
39 /*
40 * Since the global reserve is just kind of magic we don't really want
41 * to rely on it to save our bacon, so if our size is more than the
42 * delayed_refs_rsv and the global rsv then it's time to think about
43 * bailing.
44 */
45 spin_lock(&delayed_refs_rsv->lock);
46 reserved += delayed_refs_rsv->reserved;
47 if (delayed_refs_rsv->size >= reserved)
48 ret = true;
49 spin_unlock(&delayed_refs_rsv->lock);
50 return ret;
51}
52
53int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans)
54{
55 u64 num_entries =
56 atomic_read(&trans->transaction->delayed_refs.num_entries);
57 u64 avg_runtime;
58 u64 val;
59
60 smp_mb();
61 avg_runtime = trans->fs_info->avg_delayed_ref_runtime;
62 val = num_entries * avg_runtime;
63 if (val >= NSEC_PER_SEC)
64 return 1;
65 if (val >= NSEC_PER_SEC / 2)
66 return 2;
67
68 return btrfs_check_space_for_delayed_refs(trans->fs_info);
69}
70
71/**
72 * btrfs_delayed_refs_rsv_release - release a ref head's reservation.
73 * @fs_info - the fs_info for our fs.
74 * @nr - the number of items to drop.
75 *
76 * This drops the delayed ref head's count from the delayed refs rsv and frees
77 * any excess reservation we had.
78 */
79void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr)
80{
81 struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv;
82 u64 num_bytes = btrfs_calc_insert_metadata_size(fs_info, nr);
83 u64 released = 0;
84
85 released = __btrfs_block_rsv_release(fs_info, block_rsv, num_bytes,
86 NULL);
87 if (released)
88 trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
89 0, released, 0);
90}
91
92/*
93 * btrfs_update_delayed_refs_rsv - adjust the size of the delayed refs rsv
94 * @trans - the trans that may have generated delayed refs
95 *
96 * This is to be called anytime we may have adjusted trans->delayed_ref_updates,
97 * it'll calculate the additional size and add it to the delayed_refs_rsv.
98 */
99void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans)
100{
101 struct btrfs_fs_info *fs_info = trans->fs_info;
102 struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv;
103 u64 num_bytes;
104
105 if (!trans->delayed_ref_updates)
106 return;
107
108 num_bytes = btrfs_calc_insert_metadata_size(fs_info,
109 trans->delayed_ref_updates);
110 spin_lock(&delayed_rsv->lock);
111 delayed_rsv->size += num_bytes;
112 delayed_rsv->full = 0;
113 spin_unlock(&delayed_rsv->lock);
114 trans->delayed_ref_updates = 0;
115}
116
117/**
118 * btrfs_migrate_to_delayed_refs_rsv - transfer bytes to our delayed refs rsv.
119 * @fs_info - the fs info for our fs.
120 * @src - the source block rsv to transfer from.
121 * @num_bytes - the number of bytes to transfer.
122 *
123 * This transfers up to the num_bytes amount from the src rsv to the
124 * delayed_refs_rsv. Any extra bytes are returned to the space info.
125 */
126void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info,
127 struct btrfs_block_rsv *src,
128 u64 num_bytes)
129{
130 struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
131 u64 to_free = 0;
132
133 spin_lock(&src->lock);
134 src->reserved -= num_bytes;
135 src->size -= num_bytes;
136 spin_unlock(&src->lock);
137
138 spin_lock(&delayed_refs_rsv->lock);
139 if (delayed_refs_rsv->size > delayed_refs_rsv->reserved) {
140 u64 delta = delayed_refs_rsv->size -
141 delayed_refs_rsv->reserved;
142 if (num_bytes > delta) {
143 to_free = num_bytes - delta;
144 num_bytes = delta;
145 }
146 } else {
147 to_free = num_bytes;
148 num_bytes = 0;
149 }
150
151 if (num_bytes)
152 delayed_refs_rsv->reserved += num_bytes;
153 if (delayed_refs_rsv->reserved >= delayed_refs_rsv->size)
154 delayed_refs_rsv->full = 1;
155 spin_unlock(&delayed_refs_rsv->lock);
156
157 if (num_bytes)
158 trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
159 0, num_bytes, 1);
160 if (to_free)
161 btrfs_space_info_free_bytes_may_use(fs_info,
162 delayed_refs_rsv->space_info, to_free);
163}
164
165/**
166 * btrfs_delayed_refs_rsv_refill - refill based on our delayed refs usage.
167 * @fs_info - the fs_info for our fs.
168 * @flush - control how we can flush for this reservation.
169 *
170 * This will refill the delayed block_rsv up to 1 items size worth of space and
171 * will return -ENOSPC if we can't make the reservation.
172 */
173int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info,
174 enum btrfs_reserve_flush_enum flush)
175{
176 struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv;
177 u64 limit = btrfs_calc_insert_metadata_size(fs_info, 1);
178 u64 num_bytes = 0;
179 int ret = -ENOSPC;
180
181 spin_lock(&block_rsv->lock);
182 if (block_rsv->reserved < block_rsv->size) {
183 num_bytes = block_rsv->size - block_rsv->reserved;
184 num_bytes = min(num_bytes, limit);
185 }
186 spin_unlock(&block_rsv->lock);
187
188 if (!num_bytes)
189 return 0;
190
191 ret = btrfs_reserve_metadata_bytes(fs_info->extent_root, block_rsv,
192 num_bytes, flush);
193 if (ret)
194 return ret;
195 btrfs_block_rsv_add_bytes(block_rsv, num_bytes, 0);
196 trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
197 0, num_bytes, 1);
198 return 0;
199}
200
201/*
202 * compare two delayed tree backrefs with same bytenr and type
203 */
204static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref1,
205 struct btrfs_delayed_tree_ref *ref2)
206{
207 if (ref1->node.type == BTRFS_TREE_BLOCK_REF_KEY) {
208 if (ref1->root < ref2->root)
209 return -1;
210 if (ref1->root > ref2->root)
211 return 1;
212 } else {
213 if (ref1->parent < ref2->parent)
214 return -1;
215 if (ref1->parent > ref2->parent)
216 return 1;
217 }
218 return 0;
219}
220
221/*
222 * compare two delayed data backrefs with same bytenr and type
223 */
224static int comp_data_refs(struct btrfs_delayed_data_ref *ref1,
225 struct btrfs_delayed_data_ref *ref2)
226{
227 if (ref1->node.type == BTRFS_EXTENT_DATA_REF_KEY) {
228 if (ref1->root < ref2->root)
229 return -1;
230 if (ref1->root > ref2->root)
231 return 1;
232 if (ref1->objectid < ref2->objectid)
233 return -1;
234 if (ref1->objectid > ref2->objectid)
235 return 1;
236 if (ref1->offset < ref2->offset)
237 return -1;
238 if (ref1->offset > ref2->offset)
239 return 1;
240 } else {
241 if (ref1->parent < ref2->parent)
242 return -1;
243 if (ref1->parent > ref2->parent)
244 return 1;
245 }
246 return 0;
247}
248
249static int comp_refs(struct btrfs_delayed_ref_node *ref1,
250 struct btrfs_delayed_ref_node *ref2,
251 bool check_seq)
252{
253 int ret = 0;
254
255 if (ref1->type < ref2->type)
256 return -1;
257 if (ref1->type > ref2->type)
258 return 1;
259 if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
260 ref1->type == BTRFS_SHARED_BLOCK_REF_KEY)
261 ret = comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref1),
262 btrfs_delayed_node_to_tree_ref(ref2));
263 else
264 ret = comp_data_refs(btrfs_delayed_node_to_data_ref(ref1),
265 btrfs_delayed_node_to_data_ref(ref2));
266 if (ret)
267 return ret;
268 if (check_seq) {
269 if (ref1->seq < ref2->seq)
270 return -1;
271 if (ref1->seq > ref2->seq)
272 return 1;
273 }
274 return 0;
275}
276
277/* insert a new ref to head ref rbtree */
278static struct btrfs_delayed_ref_head *htree_insert(struct rb_root_cached *root,
279 struct rb_node *node)
280{
281 struct rb_node **p = &root->rb_root.rb_node;
282 struct rb_node *parent_node = NULL;
283 struct btrfs_delayed_ref_head *entry;
284 struct btrfs_delayed_ref_head *ins;
285 u64 bytenr;
286 bool leftmost = true;
287
288 ins = rb_entry(node, struct btrfs_delayed_ref_head, href_node);
289 bytenr = ins->bytenr;
290 while (*p) {
291 parent_node = *p;
292 entry = rb_entry(parent_node, struct btrfs_delayed_ref_head,
293 href_node);
294
295 if (bytenr < entry->bytenr) {
296 p = &(*p)->rb_left;
297 } else if (bytenr > entry->bytenr) {
298 p = &(*p)->rb_right;
299 leftmost = false;
300 } else {
301 return entry;
302 }
303 }
304
305 rb_link_node(node, parent_node, p);
306 rb_insert_color_cached(node, root, leftmost);
307 return NULL;
308}
309
310static struct btrfs_delayed_ref_node* tree_insert(struct rb_root_cached *root,
311 struct btrfs_delayed_ref_node *ins)
312{
313 struct rb_node **p = &root->rb_root.rb_node;
314 struct rb_node *node = &ins->ref_node;
315 struct rb_node *parent_node = NULL;
316 struct btrfs_delayed_ref_node *entry;
317 bool leftmost = true;
318
319 while (*p) {
320 int comp;
321
322 parent_node = *p;
323 entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
324 ref_node);
325 comp = comp_refs(ins, entry, true);
326 if (comp < 0) {
327 p = &(*p)->rb_left;
328 } else if (comp > 0) {
329 p = &(*p)->rb_right;
330 leftmost = false;
331 } else {
332 return entry;
333 }
334 }
335
336 rb_link_node(node, parent_node, p);
337 rb_insert_color_cached(node, root, leftmost);
338 return NULL;
339}
340
341static struct btrfs_delayed_ref_head *find_first_ref_head(
342 struct btrfs_delayed_ref_root *dr)
343{
344 struct rb_node *n;
345 struct btrfs_delayed_ref_head *entry;
346
347 n = rb_first_cached(&dr->href_root);
348 if (!n)
349 return NULL;
350
351 entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
352
353 return entry;
354}
355
356/*
357 * Find a head entry based on bytenr. This returns the delayed ref head if it
358 * was able to find one, or NULL if nothing was in that spot. If return_bigger
359 * is given, the next bigger entry is returned if no exact match is found.
360 */
361static struct btrfs_delayed_ref_head *find_ref_head(
362 struct btrfs_delayed_ref_root *dr, u64 bytenr,
363 bool return_bigger)
364{
365 struct rb_root *root = &dr->href_root.rb_root;
366 struct rb_node *n;
367 struct btrfs_delayed_ref_head *entry;
368
369 n = root->rb_node;
370 entry = NULL;
371 while (n) {
372 entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
373
374 if (bytenr < entry->bytenr)
375 n = n->rb_left;
376 else if (bytenr > entry->bytenr)
377 n = n->rb_right;
378 else
379 return entry;
380 }
381 if (entry && return_bigger) {
382 if (bytenr > entry->bytenr) {
383 n = rb_next(&entry->href_node);
384 if (!n)
385 return NULL;
386 entry = rb_entry(n, struct btrfs_delayed_ref_head,
387 href_node);
388 }
389 return entry;
390 }
391 return NULL;
392}
393
394int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs,
395 struct btrfs_delayed_ref_head *head)
396{
397 lockdep_assert_held(&delayed_refs->lock);
398 if (mutex_trylock(&head->mutex))
399 return 0;
400
401 refcount_inc(&head->refs);
402 spin_unlock(&delayed_refs->lock);
403
404 mutex_lock(&head->mutex);
405 spin_lock(&delayed_refs->lock);
406 if (RB_EMPTY_NODE(&head->href_node)) {
407 mutex_unlock(&head->mutex);
408 btrfs_put_delayed_ref_head(head);
409 return -EAGAIN;
410 }
411 btrfs_put_delayed_ref_head(head);
412 return 0;
413}
414
415static inline void drop_delayed_ref(struct btrfs_trans_handle *trans,
416 struct btrfs_delayed_ref_root *delayed_refs,
417 struct btrfs_delayed_ref_head *head,
418 struct btrfs_delayed_ref_node *ref)
419{
420 lockdep_assert_held(&head->lock);
421 rb_erase_cached(&ref->ref_node, &head->ref_tree);
422 RB_CLEAR_NODE(&ref->ref_node);
423 if (!list_empty(&ref->add_list))
424 list_del(&ref->add_list);
425 ref->in_tree = 0;
426 btrfs_put_delayed_ref(ref);
427 atomic_dec(&delayed_refs->num_entries);
428}
429
430static bool merge_ref(struct btrfs_trans_handle *trans,
431 struct btrfs_delayed_ref_root *delayed_refs,
432 struct btrfs_delayed_ref_head *head,
433 struct btrfs_delayed_ref_node *ref,
434 u64 seq)
435{
436 struct btrfs_delayed_ref_node *next;
437 struct rb_node *node = rb_next(&ref->ref_node);
438 bool done = false;
439
440 while (!done && node) {
441 int mod;
442
443 next = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
444 node = rb_next(node);
445 if (seq && next->seq >= seq)
446 break;
447 if (comp_refs(ref, next, false))
448 break;
449
450 if (ref->action == next->action) {
451 mod = next->ref_mod;
452 } else {
453 if (ref->ref_mod < next->ref_mod) {
454 swap(ref, next);
455 done = true;
456 }
457 mod = -next->ref_mod;
458 }
459
460 drop_delayed_ref(trans, delayed_refs, head, next);
461 ref->ref_mod += mod;
462 if (ref->ref_mod == 0) {
463 drop_delayed_ref(trans, delayed_refs, head, ref);
464 done = true;
465 } else {
466 /*
467 * Can't have multiples of the same ref on a tree block.
468 */
469 WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
470 ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
471 }
472 }
473
474 return done;
475}
476
477void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
478 struct btrfs_delayed_ref_root *delayed_refs,
479 struct btrfs_delayed_ref_head *head)
480{
481 struct btrfs_fs_info *fs_info = trans->fs_info;
482 struct btrfs_delayed_ref_node *ref;
483 struct rb_node *node;
484 u64 seq = 0;
485
486 lockdep_assert_held(&head->lock);
487
488 if (RB_EMPTY_ROOT(&head->ref_tree.rb_root))
489 return;
490
491 /* We don't have too many refs to merge for data. */
492 if (head->is_data)
493 return;
494
495 spin_lock(&fs_info->tree_mod_seq_lock);
496 if (!list_empty(&fs_info->tree_mod_seq_list)) {
497 struct seq_list *elem;
498
499 elem = list_first_entry(&fs_info->tree_mod_seq_list,
500 struct seq_list, list);
501 seq = elem->seq;
502 }
503 spin_unlock(&fs_info->tree_mod_seq_lock);
504
505again:
506 for (node = rb_first_cached(&head->ref_tree); node;
507 node = rb_next(node)) {
508 ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
509 if (seq && ref->seq >= seq)
510 continue;
511 if (merge_ref(trans, delayed_refs, head, ref, seq))
512 goto again;
513 }
514}
515
516int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq)
517{
518 struct seq_list *elem;
519 int ret = 0;
520
521 spin_lock(&fs_info->tree_mod_seq_lock);
522 if (!list_empty(&fs_info->tree_mod_seq_list)) {
523 elem = list_first_entry(&fs_info->tree_mod_seq_list,
524 struct seq_list, list);
525 if (seq >= elem->seq) {
526 btrfs_debug(fs_info,
527 "holding back delayed_ref %#x.%x, lowest is %#x.%x",
528 (u32)(seq >> 32), (u32)seq,
529 (u32)(elem->seq >> 32), (u32)elem->seq);
530 ret = 1;
531 }
532 }
533
534 spin_unlock(&fs_info->tree_mod_seq_lock);
535 return ret;
536}
537
538struct btrfs_delayed_ref_head *btrfs_select_ref_head(
539 struct btrfs_delayed_ref_root *delayed_refs)
540{
541 struct btrfs_delayed_ref_head *head;
542
543again:
544 head = find_ref_head(delayed_refs, delayed_refs->run_delayed_start,
545 true);
546 if (!head && delayed_refs->run_delayed_start != 0) {
547 delayed_refs->run_delayed_start = 0;
548 head = find_first_ref_head(delayed_refs);
549 }
550 if (!head)
551 return NULL;
552
553 while (head->processing) {
554 struct rb_node *node;
555
556 node = rb_next(&head->href_node);
557 if (!node) {
558 if (delayed_refs->run_delayed_start == 0)
559 return NULL;
560 delayed_refs->run_delayed_start = 0;
561 goto again;
562 }
563 head = rb_entry(node, struct btrfs_delayed_ref_head,
564 href_node);
565 }
566
567 head->processing = 1;
568 WARN_ON(delayed_refs->num_heads_ready == 0);
569 delayed_refs->num_heads_ready--;
570 delayed_refs->run_delayed_start = head->bytenr +
571 head->num_bytes;
572 return head;
573}
574
575void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
576 struct btrfs_delayed_ref_head *head)
577{
578 lockdep_assert_held(&delayed_refs->lock);
579 lockdep_assert_held(&head->lock);
580
581 rb_erase_cached(&head->href_node, &delayed_refs->href_root);
582 RB_CLEAR_NODE(&head->href_node);
583 atomic_dec(&delayed_refs->num_entries);
584 delayed_refs->num_heads--;
585 if (head->processing == 0)
586 delayed_refs->num_heads_ready--;
587}
588
589/*
590 * Helper to insert the ref_node to the tail or merge with tail.
591 *
592 * Return 0 for insert.
593 * Return >0 for merge.
594 */
595static int insert_delayed_ref(struct btrfs_trans_handle *trans,
596 struct btrfs_delayed_ref_root *root,
597 struct btrfs_delayed_ref_head *href,
598 struct btrfs_delayed_ref_node *ref)
599{
600 struct btrfs_delayed_ref_node *exist;
601 int mod;
602 int ret = 0;
603
604 spin_lock(&href->lock);
605 exist = tree_insert(&href->ref_tree, ref);
606 if (!exist)
607 goto inserted;
608
609 /* Now we are sure we can merge */
610 ret = 1;
611 if (exist->action == ref->action) {
612 mod = ref->ref_mod;
613 } else {
614 /* Need to change action */
615 if (exist->ref_mod < ref->ref_mod) {
616 exist->action = ref->action;
617 mod = -exist->ref_mod;
618 exist->ref_mod = ref->ref_mod;
619 if (ref->action == BTRFS_ADD_DELAYED_REF)
620 list_add_tail(&exist->add_list,
621 &href->ref_add_list);
622 else if (ref->action == BTRFS_DROP_DELAYED_REF) {
623 ASSERT(!list_empty(&exist->add_list));
624 list_del(&exist->add_list);
625 } else {
626 ASSERT(0);
627 }
628 } else
629 mod = -ref->ref_mod;
630 }
631 exist->ref_mod += mod;
632
633 /* remove existing tail if its ref_mod is zero */
634 if (exist->ref_mod == 0)
635 drop_delayed_ref(trans, root, href, exist);
636 spin_unlock(&href->lock);
637 return ret;
638inserted:
639 if (ref->action == BTRFS_ADD_DELAYED_REF)
640 list_add_tail(&ref->add_list, &href->ref_add_list);
641 atomic_inc(&root->num_entries);
642 spin_unlock(&href->lock);
643 return ret;
644}
645
646/*
647 * helper function to update the accounting in the head ref
648 * existing and update must have the same bytenr
649 */
650static noinline void update_existing_head_ref(struct btrfs_trans_handle *trans,
651 struct btrfs_delayed_ref_head *existing,
652 struct btrfs_delayed_ref_head *update,
653 int *old_ref_mod_ret)
654{
655 struct btrfs_delayed_ref_root *delayed_refs =
656 &trans->transaction->delayed_refs;
657 struct btrfs_fs_info *fs_info = trans->fs_info;
658 int old_ref_mod;
659
660 BUG_ON(existing->is_data != update->is_data);
661
662 spin_lock(&existing->lock);
663 if (update->must_insert_reserved) {
664 /* if the extent was freed and then
665 * reallocated before the delayed ref
666 * entries were processed, we can end up
667 * with an existing head ref without
668 * the must_insert_reserved flag set.
669 * Set it again here
670 */
671 existing->must_insert_reserved = update->must_insert_reserved;
672
673 /*
674 * update the num_bytes so we make sure the accounting
675 * is done correctly
676 */
677 existing->num_bytes = update->num_bytes;
678
679 }
680
681 if (update->extent_op) {
682 if (!existing->extent_op) {
683 existing->extent_op = update->extent_op;
684 } else {
685 if (update->extent_op->update_key) {
686 memcpy(&existing->extent_op->key,
687 &update->extent_op->key,
688 sizeof(update->extent_op->key));
689 existing->extent_op->update_key = true;
690 }
691 if (update->extent_op->update_flags) {
692 existing->extent_op->flags_to_set |=
693 update->extent_op->flags_to_set;
694 existing->extent_op->update_flags = true;
695 }
696 btrfs_free_delayed_extent_op(update->extent_op);
697 }
698 }
699 /*
700 * update the reference mod on the head to reflect this new operation,
701 * only need the lock for this case cause we could be processing it
702 * currently, for refs we just added we know we're a-ok.
703 */
704 old_ref_mod = existing->total_ref_mod;
705 if (old_ref_mod_ret)
706 *old_ref_mod_ret = old_ref_mod;
707 existing->ref_mod += update->ref_mod;
708 existing->total_ref_mod += update->ref_mod;
709
710 /*
711 * If we are going to from a positive ref mod to a negative or vice
712 * versa we need to make sure to adjust pending_csums accordingly.
713 */
714 if (existing->is_data) {
715 u64 csum_leaves =
716 btrfs_csum_bytes_to_leaves(fs_info,
717 existing->num_bytes);
718
719 if (existing->total_ref_mod >= 0 && old_ref_mod < 0) {
720 delayed_refs->pending_csums -= existing->num_bytes;
721 btrfs_delayed_refs_rsv_release(fs_info, csum_leaves);
722 }
723 if (existing->total_ref_mod < 0 && old_ref_mod >= 0) {
724 delayed_refs->pending_csums += existing->num_bytes;
725 trans->delayed_ref_updates += csum_leaves;
726 }
727 }
728 spin_unlock(&existing->lock);
729}
730
731static void init_delayed_ref_head(struct btrfs_delayed_ref_head *head_ref,
732 struct btrfs_qgroup_extent_record *qrecord,
733 u64 bytenr, u64 num_bytes, u64 ref_root,
734 u64 reserved, int action, bool is_data,
735 bool is_system)
736{
737 int count_mod = 1;
738 int must_insert_reserved = 0;
739
740 /* If reserved is provided, it must be a data extent. */
741 BUG_ON(!is_data && reserved);
742
743 /*
744 * The head node stores the sum of all the mods, so dropping a ref
745 * should drop the sum in the head node by one.
746 */
747 if (action == BTRFS_UPDATE_DELAYED_HEAD)
748 count_mod = 0;
749 else if (action == BTRFS_DROP_DELAYED_REF)
750 count_mod = -1;
751
752 /*
753 * BTRFS_ADD_DELAYED_EXTENT means that we need to update the reserved
754 * accounting when the extent is finally added, or if a later
755 * modification deletes the delayed ref without ever inserting the
756 * extent into the extent allocation tree. ref->must_insert_reserved
757 * is the flag used to record that accounting mods are required.
758 *
759 * Once we record must_insert_reserved, switch the action to
760 * BTRFS_ADD_DELAYED_REF because other special casing is not required.
761 */
762 if (action == BTRFS_ADD_DELAYED_EXTENT)
763 must_insert_reserved = 1;
764 else
765 must_insert_reserved = 0;
766
767 refcount_set(&head_ref->refs, 1);
768 head_ref->bytenr = bytenr;
769 head_ref->num_bytes = num_bytes;
770 head_ref->ref_mod = count_mod;
771 head_ref->must_insert_reserved = must_insert_reserved;
772 head_ref->is_data = is_data;
773 head_ref->is_system = is_system;
774 head_ref->ref_tree = RB_ROOT_CACHED;
775 INIT_LIST_HEAD(&head_ref->ref_add_list);
776 RB_CLEAR_NODE(&head_ref->href_node);
777 head_ref->processing = 0;
778 head_ref->total_ref_mod = count_mod;
779 spin_lock_init(&head_ref->lock);
780 mutex_init(&head_ref->mutex);
781
782 if (qrecord) {
783 if (ref_root && reserved) {
784 qrecord->data_rsv = reserved;
785 qrecord->data_rsv_refroot = ref_root;
786 }
787 qrecord->bytenr = bytenr;
788 qrecord->num_bytes = num_bytes;
789 qrecord->old_roots = NULL;
790 }
791}
792
793/*
794 * helper function to actually insert a head node into the rbtree.
795 * this does all the dirty work in terms of maintaining the correct
796 * overall modification count.
797 */
798static noinline struct btrfs_delayed_ref_head *
799add_delayed_ref_head(struct btrfs_trans_handle *trans,
800 struct btrfs_delayed_ref_head *head_ref,
801 struct btrfs_qgroup_extent_record *qrecord,
802 int action, int *qrecord_inserted_ret,
803 int *old_ref_mod, int *new_ref_mod)
804{
805 struct btrfs_delayed_ref_head *existing;
806 struct btrfs_delayed_ref_root *delayed_refs;
807 int qrecord_inserted = 0;
808
809 delayed_refs = &trans->transaction->delayed_refs;
810
811 /* Record qgroup extent info if provided */
812 if (qrecord) {
813 if (btrfs_qgroup_trace_extent_nolock(trans->fs_info,
814 delayed_refs, qrecord))
815 kfree(qrecord);
816 else
817 qrecord_inserted = 1;
818 }
819
820 trace_add_delayed_ref_head(trans->fs_info, head_ref, action);
821
822 existing = htree_insert(&delayed_refs->href_root,
823 &head_ref->href_node);
824 if (existing) {
825 update_existing_head_ref(trans, existing, head_ref,
826 old_ref_mod);
827 /*
828 * we've updated the existing ref, free the newly
829 * allocated ref
830 */
831 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
832 head_ref = existing;
833 } else {
834 if (old_ref_mod)
835 *old_ref_mod = 0;
836 if (head_ref->is_data && head_ref->ref_mod < 0) {
837 delayed_refs->pending_csums += head_ref->num_bytes;
838 trans->delayed_ref_updates +=
839 btrfs_csum_bytes_to_leaves(trans->fs_info,
840 head_ref->num_bytes);
841 }
842 delayed_refs->num_heads++;
843 delayed_refs->num_heads_ready++;
844 atomic_inc(&delayed_refs->num_entries);
845 trans->delayed_ref_updates++;
846 }
847 if (qrecord_inserted_ret)
848 *qrecord_inserted_ret = qrecord_inserted;
849 if (new_ref_mod)
850 *new_ref_mod = head_ref->total_ref_mod;
851
852 return head_ref;
853}
854
855/*
856 * init_delayed_ref_common - Initialize the structure which represents a
857 * modification to a an extent.
858 *
859 * @fs_info: Internal to the mounted filesystem mount structure.
860 *
861 * @ref: The structure which is going to be initialized.
862 *
863 * @bytenr: The logical address of the extent for which a modification is
864 * going to be recorded.
865 *
866 * @num_bytes: Size of the extent whose modification is being recorded.
867 *
868 * @ref_root: The id of the root where this modification has originated, this
869 * can be either one of the well-known metadata trees or the
870 * subvolume id which references this extent.
871 *
872 * @action: Can be one of BTRFS_ADD_DELAYED_REF/BTRFS_DROP_DELAYED_REF or
873 * BTRFS_ADD_DELAYED_EXTENT
874 *
875 * @ref_type: Holds the type of the extent which is being recorded, can be
876 * one of BTRFS_SHARED_BLOCK_REF_KEY/BTRFS_TREE_BLOCK_REF_KEY
877 * when recording a metadata extent or BTRFS_SHARED_DATA_REF_KEY/
878 * BTRFS_EXTENT_DATA_REF_KEY when recording data extent
879 */
880static void init_delayed_ref_common(struct btrfs_fs_info *fs_info,
881 struct btrfs_delayed_ref_node *ref,
882 u64 bytenr, u64 num_bytes, u64 ref_root,
883 int action, u8 ref_type)
884{
885 u64 seq = 0;
886
887 if (action == BTRFS_ADD_DELAYED_EXTENT)
888 action = BTRFS_ADD_DELAYED_REF;
889
890 if (is_fstree(ref_root))
891 seq = atomic64_read(&fs_info->tree_mod_seq);
892
893 refcount_set(&ref->refs, 1);
894 ref->bytenr = bytenr;
895 ref->num_bytes = num_bytes;
896 ref->ref_mod = 1;
897 ref->action = action;
898 ref->is_head = 0;
899 ref->in_tree = 1;
900 ref->seq = seq;
901 ref->type = ref_type;
902 RB_CLEAR_NODE(&ref->ref_node);
903 INIT_LIST_HEAD(&ref->add_list);
904}
905
906/*
907 * add a delayed tree ref. This does all of the accounting required
908 * to make sure the delayed ref is eventually processed before this
909 * transaction commits.
910 */
911int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
912 struct btrfs_ref *generic_ref,
913 struct btrfs_delayed_extent_op *extent_op,
914 int *old_ref_mod, int *new_ref_mod)
915{
916 struct btrfs_fs_info *fs_info = trans->fs_info;
917 struct btrfs_delayed_tree_ref *ref;
918 struct btrfs_delayed_ref_head *head_ref;
919 struct btrfs_delayed_ref_root *delayed_refs;
920 struct btrfs_qgroup_extent_record *record = NULL;
921 int qrecord_inserted;
922 bool is_system;
923 int action = generic_ref->action;
924 int level = generic_ref->tree_ref.level;
925 int ret;
926 u64 bytenr = generic_ref->bytenr;
927 u64 num_bytes = generic_ref->len;
928 u64 parent = generic_ref->parent;
929 u8 ref_type;
930
931 is_system = (generic_ref->real_root == BTRFS_CHUNK_TREE_OBJECTID);
932
933 ASSERT(generic_ref->type == BTRFS_REF_METADATA && generic_ref->action);
934 BUG_ON(extent_op && extent_op->is_data);
935 ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS);
936 if (!ref)
937 return -ENOMEM;
938
939 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
940 if (!head_ref) {
941 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
942 return -ENOMEM;
943 }
944
945 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
946 is_fstree(generic_ref->real_root) &&
947 is_fstree(generic_ref->tree_ref.root) &&
948 !generic_ref->skip_qgroup) {
949 record = kzalloc(sizeof(*record), GFP_NOFS);
950 if (!record) {
951 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
952 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
953 return -ENOMEM;
954 }
955 }
956
957 if (parent)
958 ref_type = BTRFS_SHARED_BLOCK_REF_KEY;
959 else
960 ref_type = BTRFS_TREE_BLOCK_REF_KEY;
961
962 init_delayed_ref_common(fs_info, &ref->node, bytenr, num_bytes,
963 generic_ref->tree_ref.root, action, ref_type);
964 ref->root = generic_ref->tree_ref.root;
965 ref->parent = parent;
966 ref->level = level;
967
968 init_delayed_ref_head(head_ref, record, bytenr, num_bytes,
969 generic_ref->tree_ref.root, 0, action, false,
970 is_system);
971 head_ref->extent_op = extent_op;
972
973 delayed_refs = &trans->transaction->delayed_refs;
974 spin_lock(&delayed_refs->lock);
975
976 /*
977 * insert both the head node and the new ref without dropping
978 * the spin lock
979 */
980 head_ref = add_delayed_ref_head(trans, head_ref, record,
981 action, &qrecord_inserted,
982 old_ref_mod, new_ref_mod);
983
984 ret = insert_delayed_ref(trans, delayed_refs, head_ref, &ref->node);
985 spin_unlock(&delayed_refs->lock);
986
987 /*
988 * Need to update the delayed_refs_rsv with any changes we may have
989 * made.
990 */
991 btrfs_update_delayed_refs_rsv(trans);
992
993 trace_add_delayed_tree_ref(fs_info, &ref->node, ref,
994 action == BTRFS_ADD_DELAYED_EXTENT ?
995 BTRFS_ADD_DELAYED_REF : action);
996 if (ret > 0)
997 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
998
999 if (qrecord_inserted)
1000 btrfs_qgroup_trace_extent_post(fs_info, record);
1001
1002 return 0;
1003}
1004
1005/*
1006 * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
1007 */
1008int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
1009 struct btrfs_ref *generic_ref,
1010 u64 reserved, int *old_ref_mod,
1011 int *new_ref_mod)
1012{
1013 struct btrfs_fs_info *fs_info = trans->fs_info;
1014 struct btrfs_delayed_data_ref *ref;
1015 struct btrfs_delayed_ref_head *head_ref;
1016 struct btrfs_delayed_ref_root *delayed_refs;
1017 struct btrfs_qgroup_extent_record *record = NULL;
1018 int qrecord_inserted;
1019 int action = generic_ref->action;
1020 int ret;
1021 u64 bytenr = generic_ref->bytenr;
1022 u64 num_bytes = generic_ref->len;
1023 u64 parent = generic_ref->parent;
1024 u64 ref_root = generic_ref->data_ref.ref_root;
1025 u64 owner = generic_ref->data_ref.ino;
1026 u64 offset = generic_ref->data_ref.offset;
1027 u8 ref_type;
1028
1029 ASSERT(generic_ref->type == BTRFS_REF_DATA && action);
1030 ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS);
1031 if (!ref)
1032 return -ENOMEM;
1033
1034 if (parent)
1035 ref_type = BTRFS_SHARED_DATA_REF_KEY;
1036 else
1037 ref_type = BTRFS_EXTENT_DATA_REF_KEY;
1038 init_delayed_ref_common(fs_info, &ref->node, bytenr, num_bytes,
1039 ref_root, action, ref_type);
1040 ref->root = ref_root;
1041 ref->parent = parent;
1042 ref->objectid = owner;
1043 ref->offset = offset;
1044
1045
1046 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
1047 if (!head_ref) {
1048 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
1049 return -ENOMEM;
1050 }
1051
1052 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
1053 is_fstree(ref_root) &&
1054 is_fstree(generic_ref->real_root) &&
1055 !generic_ref->skip_qgroup) {
1056 record = kzalloc(sizeof(*record), GFP_NOFS);
1057 if (!record) {
1058 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
1059 kmem_cache_free(btrfs_delayed_ref_head_cachep,
1060 head_ref);
1061 return -ENOMEM;
1062 }
1063 }
1064
1065 init_delayed_ref_head(head_ref, record, bytenr, num_bytes, ref_root,
1066 reserved, action, true, false);
1067 head_ref->extent_op = NULL;
1068
1069 delayed_refs = &trans->transaction->delayed_refs;
1070 spin_lock(&delayed_refs->lock);
1071
1072 /*
1073 * insert both the head node and the new ref without dropping
1074 * the spin lock
1075 */
1076 head_ref = add_delayed_ref_head(trans, head_ref, record,
1077 action, &qrecord_inserted,
1078 old_ref_mod, new_ref_mod);
1079
1080 ret = insert_delayed_ref(trans, delayed_refs, head_ref, &ref->node);
1081 spin_unlock(&delayed_refs->lock);
1082
1083 /*
1084 * Need to update the delayed_refs_rsv with any changes we may have
1085 * made.
1086 */
1087 btrfs_update_delayed_refs_rsv(trans);
1088
1089 trace_add_delayed_data_ref(trans->fs_info, &ref->node, ref,
1090 action == BTRFS_ADD_DELAYED_EXTENT ?
1091 BTRFS_ADD_DELAYED_REF : action);
1092 if (ret > 0)
1093 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
1094
1095
1096 if (qrecord_inserted)
1097 return btrfs_qgroup_trace_extent_post(fs_info, record);
1098 return 0;
1099}
1100
1101int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
1102 u64 bytenr, u64 num_bytes,
1103 struct btrfs_delayed_extent_op *extent_op)
1104{
1105 struct btrfs_delayed_ref_head *head_ref;
1106 struct btrfs_delayed_ref_root *delayed_refs;
1107
1108 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
1109 if (!head_ref)
1110 return -ENOMEM;
1111
1112 init_delayed_ref_head(head_ref, NULL, bytenr, num_bytes, 0, 0,
1113 BTRFS_UPDATE_DELAYED_HEAD, extent_op->is_data,
1114 false);
1115 head_ref->extent_op = extent_op;
1116
1117 delayed_refs = &trans->transaction->delayed_refs;
1118 spin_lock(&delayed_refs->lock);
1119
1120 add_delayed_ref_head(trans, head_ref, NULL, BTRFS_UPDATE_DELAYED_HEAD,
1121 NULL, NULL, NULL);
1122
1123 spin_unlock(&delayed_refs->lock);
1124
1125 /*
1126 * Need to update the delayed_refs_rsv with any changes we may have
1127 * made.
1128 */
1129 btrfs_update_delayed_refs_rsv(trans);
1130 return 0;
1131}
1132
1133/*
1134 * This does a simple search for the head node for a given extent. Returns the
1135 * head node if found, or NULL if not.
1136 */
1137struct btrfs_delayed_ref_head *
1138btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, u64 bytenr)
1139{
1140 lockdep_assert_held(&delayed_refs->lock);
1141
1142 return find_ref_head(delayed_refs, bytenr, false);
1143}
1144
1145void __cold btrfs_delayed_ref_exit(void)
1146{
1147 kmem_cache_destroy(btrfs_delayed_ref_head_cachep);
1148 kmem_cache_destroy(btrfs_delayed_tree_ref_cachep);
1149 kmem_cache_destroy(btrfs_delayed_data_ref_cachep);
1150 kmem_cache_destroy(btrfs_delayed_extent_op_cachep);
1151}
1152
1153int __init btrfs_delayed_ref_init(void)
1154{
1155 btrfs_delayed_ref_head_cachep = kmem_cache_create(
1156 "btrfs_delayed_ref_head",
1157 sizeof(struct btrfs_delayed_ref_head), 0,
1158 SLAB_MEM_SPREAD, NULL);
1159 if (!btrfs_delayed_ref_head_cachep)
1160 goto fail;
1161
1162 btrfs_delayed_tree_ref_cachep = kmem_cache_create(
1163 "btrfs_delayed_tree_ref",
1164 sizeof(struct btrfs_delayed_tree_ref), 0,
1165 SLAB_MEM_SPREAD, NULL);
1166 if (!btrfs_delayed_tree_ref_cachep)
1167 goto fail;
1168
1169 btrfs_delayed_data_ref_cachep = kmem_cache_create(
1170 "btrfs_delayed_data_ref",
1171 sizeof(struct btrfs_delayed_data_ref), 0,
1172 SLAB_MEM_SPREAD, NULL);
1173 if (!btrfs_delayed_data_ref_cachep)
1174 goto fail;
1175
1176 btrfs_delayed_extent_op_cachep = kmem_cache_create(
1177 "btrfs_delayed_extent_op",
1178 sizeof(struct btrfs_delayed_extent_op), 0,
1179 SLAB_MEM_SPREAD, NULL);
1180 if (!btrfs_delayed_extent_op_cachep)
1181 goto fail;
1182
1183 return 0;
1184fail:
1185 btrfs_delayed_ref_exit();
1186 return -ENOMEM;
1187}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2009 Oracle. All rights reserved.
4 */
5
6#include <linux/sched.h>
7#include <linux/slab.h>
8#include <linux/sort.h>
9#include "ctree.h"
10#include "delayed-ref.h"
11#include "transaction.h"
12#include "qgroup.h"
13
14struct kmem_cache *btrfs_delayed_ref_head_cachep;
15struct kmem_cache *btrfs_delayed_tree_ref_cachep;
16struct kmem_cache *btrfs_delayed_data_ref_cachep;
17struct kmem_cache *btrfs_delayed_extent_op_cachep;
18/*
19 * delayed back reference update tracking. For subvolume trees
20 * we queue up extent allocations and backref maintenance for
21 * delayed processing. This avoids deep call chains where we
22 * add extents in the middle of btrfs_search_slot, and it allows
23 * us to buffer up frequently modified backrefs in an rb tree instead
24 * of hammering updates on the extent allocation tree.
25 */
26
27/*
28 * compare two delayed tree backrefs with same bytenr and type
29 */
30static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref1,
31 struct btrfs_delayed_tree_ref *ref2)
32{
33 if (ref1->node.type == BTRFS_TREE_BLOCK_REF_KEY) {
34 if (ref1->root < ref2->root)
35 return -1;
36 if (ref1->root > ref2->root)
37 return 1;
38 } else {
39 if (ref1->parent < ref2->parent)
40 return -1;
41 if (ref1->parent > ref2->parent)
42 return 1;
43 }
44 return 0;
45}
46
47/*
48 * compare two delayed data backrefs with same bytenr and type
49 */
50static int comp_data_refs(struct btrfs_delayed_data_ref *ref1,
51 struct btrfs_delayed_data_ref *ref2)
52{
53 if (ref1->node.type == BTRFS_EXTENT_DATA_REF_KEY) {
54 if (ref1->root < ref2->root)
55 return -1;
56 if (ref1->root > ref2->root)
57 return 1;
58 if (ref1->objectid < ref2->objectid)
59 return -1;
60 if (ref1->objectid > ref2->objectid)
61 return 1;
62 if (ref1->offset < ref2->offset)
63 return -1;
64 if (ref1->offset > ref2->offset)
65 return 1;
66 } else {
67 if (ref1->parent < ref2->parent)
68 return -1;
69 if (ref1->parent > ref2->parent)
70 return 1;
71 }
72 return 0;
73}
74
75static int comp_refs(struct btrfs_delayed_ref_node *ref1,
76 struct btrfs_delayed_ref_node *ref2,
77 bool check_seq)
78{
79 int ret = 0;
80
81 if (ref1->type < ref2->type)
82 return -1;
83 if (ref1->type > ref2->type)
84 return 1;
85 if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
86 ref1->type == BTRFS_SHARED_BLOCK_REF_KEY)
87 ret = comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref1),
88 btrfs_delayed_node_to_tree_ref(ref2));
89 else
90 ret = comp_data_refs(btrfs_delayed_node_to_data_ref(ref1),
91 btrfs_delayed_node_to_data_ref(ref2));
92 if (ret)
93 return ret;
94 if (check_seq) {
95 if (ref1->seq < ref2->seq)
96 return -1;
97 if (ref1->seq > ref2->seq)
98 return 1;
99 }
100 return 0;
101}
102
103/* insert a new ref to head ref rbtree */
104static struct btrfs_delayed_ref_head *htree_insert(struct rb_root *root,
105 struct rb_node *node)
106{
107 struct rb_node **p = &root->rb_node;
108 struct rb_node *parent_node = NULL;
109 struct btrfs_delayed_ref_head *entry;
110 struct btrfs_delayed_ref_head *ins;
111 u64 bytenr;
112
113 ins = rb_entry(node, struct btrfs_delayed_ref_head, href_node);
114 bytenr = ins->bytenr;
115 while (*p) {
116 parent_node = *p;
117 entry = rb_entry(parent_node, struct btrfs_delayed_ref_head,
118 href_node);
119
120 if (bytenr < entry->bytenr)
121 p = &(*p)->rb_left;
122 else if (bytenr > entry->bytenr)
123 p = &(*p)->rb_right;
124 else
125 return entry;
126 }
127
128 rb_link_node(node, parent_node, p);
129 rb_insert_color(node, root);
130 return NULL;
131}
132
133static struct btrfs_delayed_ref_node* tree_insert(struct rb_root *root,
134 struct btrfs_delayed_ref_node *ins)
135{
136 struct rb_node **p = &root->rb_node;
137 struct rb_node *node = &ins->ref_node;
138 struct rb_node *parent_node = NULL;
139 struct btrfs_delayed_ref_node *entry;
140
141 while (*p) {
142 int comp;
143
144 parent_node = *p;
145 entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
146 ref_node);
147 comp = comp_refs(ins, entry, true);
148 if (comp < 0)
149 p = &(*p)->rb_left;
150 else if (comp > 0)
151 p = &(*p)->rb_right;
152 else
153 return entry;
154 }
155
156 rb_link_node(node, parent_node, p);
157 rb_insert_color(node, root);
158 return NULL;
159}
160
161/*
162 * find an head entry based on bytenr. This returns the delayed ref
163 * head if it was able to find one, or NULL if nothing was in that spot.
164 * If return_bigger is given, the next bigger entry is returned if no exact
165 * match is found.
166 */
167static struct btrfs_delayed_ref_head *
168find_ref_head(struct rb_root *root, u64 bytenr,
169 int return_bigger)
170{
171 struct rb_node *n;
172 struct btrfs_delayed_ref_head *entry;
173
174 n = root->rb_node;
175 entry = NULL;
176 while (n) {
177 entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
178
179 if (bytenr < entry->bytenr)
180 n = n->rb_left;
181 else if (bytenr > entry->bytenr)
182 n = n->rb_right;
183 else
184 return entry;
185 }
186 if (entry && return_bigger) {
187 if (bytenr > entry->bytenr) {
188 n = rb_next(&entry->href_node);
189 if (!n)
190 n = rb_first(root);
191 entry = rb_entry(n, struct btrfs_delayed_ref_head,
192 href_node);
193 return entry;
194 }
195 return entry;
196 }
197 return NULL;
198}
199
200int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
201 struct btrfs_delayed_ref_head *head)
202{
203 struct btrfs_delayed_ref_root *delayed_refs;
204
205 delayed_refs = &trans->transaction->delayed_refs;
206 lockdep_assert_held(&delayed_refs->lock);
207 if (mutex_trylock(&head->mutex))
208 return 0;
209
210 refcount_inc(&head->refs);
211 spin_unlock(&delayed_refs->lock);
212
213 mutex_lock(&head->mutex);
214 spin_lock(&delayed_refs->lock);
215 if (RB_EMPTY_NODE(&head->href_node)) {
216 mutex_unlock(&head->mutex);
217 btrfs_put_delayed_ref_head(head);
218 return -EAGAIN;
219 }
220 btrfs_put_delayed_ref_head(head);
221 return 0;
222}
223
224static inline void drop_delayed_ref(struct btrfs_trans_handle *trans,
225 struct btrfs_delayed_ref_root *delayed_refs,
226 struct btrfs_delayed_ref_head *head,
227 struct btrfs_delayed_ref_node *ref)
228{
229 lockdep_assert_held(&head->lock);
230 rb_erase(&ref->ref_node, &head->ref_tree);
231 RB_CLEAR_NODE(&ref->ref_node);
232 if (!list_empty(&ref->add_list))
233 list_del(&ref->add_list);
234 ref->in_tree = 0;
235 btrfs_put_delayed_ref(ref);
236 atomic_dec(&delayed_refs->num_entries);
237 if (trans->delayed_ref_updates)
238 trans->delayed_ref_updates--;
239}
240
241static bool merge_ref(struct btrfs_trans_handle *trans,
242 struct btrfs_delayed_ref_root *delayed_refs,
243 struct btrfs_delayed_ref_head *head,
244 struct btrfs_delayed_ref_node *ref,
245 u64 seq)
246{
247 struct btrfs_delayed_ref_node *next;
248 struct rb_node *node = rb_next(&ref->ref_node);
249 bool done = false;
250
251 while (!done && node) {
252 int mod;
253
254 next = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
255 node = rb_next(node);
256 if (seq && next->seq >= seq)
257 break;
258 if (comp_refs(ref, next, false))
259 break;
260
261 if (ref->action == next->action) {
262 mod = next->ref_mod;
263 } else {
264 if (ref->ref_mod < next->ref_mod) {
265 swap(ref, next);
266 done = true;
267 }
268 mod = -next->ref_mod;
269 }
270
271 drop_delayed_ref(trans, delayed_refs, head, next);
272 ref->ref_mod += mod;
273 if (ref->ref_mod == 0) {
274 drop_delayed_ref(trans, delayed_refs, head, ref);
275 done = true;
276 } else {
277 /*
278 * Can't have multiples of the same ref on a tree block.
279 */
280 WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
281 ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
282 }
283 }
284
285 return done;
286}
287
288void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
289 struct btrfs_fs_info *fs_info,
290 struct btrfs_delayed_ref_root *delayed_refs,
291 struct btrfs_delayed_ref_head *head)
292{
293 struct btrfs_delayed_ref_node *ref;
294 struct rb_node *node;
295 u64 seq = 0;
296
297 lockdep_assert_held(&head->lock);
298
299 if (RB_EMPTY_ROOT(&head->ref_tree))
300 return;
301
302 /* We don't have too many refs to merge for data. */
303 if (head->is_data)
304 return;
305
306 spin_lock(&fs_info->tree_mod_seq_lock);
307 if (!list_empty(&fs_info->tree_mod_seq_list)) {
308 struct seq_list *elem;
309
310 elem = list_first_entry(&fs_info->tree_mod_seq_list,
311 struct seq_list, list);
312 seq = elem->seq;
313 }
314 spin_unlock(&fs_info->tree_mod_seq_lock);
315
316again:
317 for (node = rb_first(&head->ref_tree); node; node = rb_next(node)) {
318 ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
319 if (seq && ref->seq >= seq)
320 continue;
321 if (merge_ref(trans, delayed_refs, head, ref, seq))
322 goto again;
323 }
324}
325
326int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
327 struct btrfs_delayed_ref_root *delayed_refs,
328 u64 seq)
329{
330 struct seq_list *elem;
331 int ret = 0;
332
333 spin_lock(&fs_info->tree_mod_seq_lock);
334 if (!list_empty(&fs_info->tree_mod_seq_list)) {
335 elem = list_first_entry(&fs_info->tree_mod_seq_list,
336 struct seq_list, list);
337 if (seq >= elem->seq) {
338 btrfs_debug(fs_info,
339 "holding back delayed_ref %#x.%x, lowest is %#x.%x (%p)",
340 (u32)(seq >> 32), (u32)seq,
341 (u32)(elem->seq >> 32), (u32)elem->seq,
342 delayed_refs);
343 ret = 1;
344 }
345 }
346
347 spin_unlock(&fs_info->tree_mod_seq_lock);
348 return ret;
349}
350
351struct btrfs_delayed_ref_head *
352btrfs_select_ref_head(struct btrfs_trans_handle *trans)
353{
354 struct btrfs_delayed_ref_root *delayed_refs;
355 struct btrfs_delayed_ref_head *head;
356 u64 start;
357 bool loop = false;
358
359 delayed_refs = &trans->transaction->delayed_refs;
360
361again:
362 start = delayed_refs->run_delayed_start;
363 head = find_ref_head(&delayed_refs->href_root, start, 1);
364 if (!head && !loop) {
365 delayed_refs->run_delayed_start = 0;
366 start = 0;
367 loop = true;
368 head = find_ref_head(&delayed_refs->href_root, start, 1);
369 if (!head)
370 return NULL;
371 } else if (!head && loop) {
372 return NULL;
373 }
374
375 while (head->processing) {
376 struct rb_node *node;
377
378 node = rb_next(&head->href_node);
379 if (!node) {
380 if (loop)
381 return NULL;
382 delayed_refs->run_delayed_start = 0;
383 start = 0;
384 loop = true;
385 goto again;
386 }
387 head = rb_entry(node, struct btrfs_delayed_ref_head,
388 href_node);
389 }
390
391 head->processing = 1;
392 WARN_ON(delayed_refs->num_heads_ready == 0);
393 delayed_refs->num_heads_ready--;
394 delayed_refs->run_delayed_start = head->bytenr +
395 head->num_bytes;
396 return head;
397}
398
399/*
400 * Helper to insert the ref_node to the tail or merge with tail.
401 *
402 * Return 0 for insert.
403 * Return >0 for merge.
404 */
405static int insert_delayed_ref(struct btrfs_trans_handle *trans,
406 struct btrfs_delayed_ref_root *root,
407 struct btrfs_delayed_ref_head *href,
408 struct btrfs_delayed_ref_node *ref)
409{
410 struct btrfs_delayed_ref_node *exist;
411 int mod;
412 int ret = 0;
413
414 spin_lock(&href->lock);
415 exist = tree_insert(&href->ref_tree, ref);
416 if (!exist)
417 goto inserted;
418
419 /* Now we are sure we can merge */
420 ret = 1;
421 if (exist->action == ref->action) {
422 mod = ref->ref_mod;
423 } else {
424 /* Need to change action */
425 if (exist->ref_mod < ref->ref_mod) {
426 exist->action = ref->action;
427 mod = -exist->ref_mod;
428 exist->ref_mod = ref->ref_mod;
429 if (ref->action == BTRFS_ADD_DELAYED_REF)
430 list_add_tail(&exist->add_list,
431 &href->ref_add_list);
432 else if (ref->action == BTRFS_DROP_DELAYED_REF) {
433 ASSERT(!list_empty(&exist->add_list));
434 list_del(&exist->add_list);
435 } else {
436 ASSERT(0);
437 }
438 } else
439 mod = -ref->ref_mod;
440 }
441 exist->ref_mod += mod;
442
443 /* remove existing tail if its ref_mod is zero */
444 if (exist->ref_mod == 0)
445 drop_delayed_ref(trans, root, href, exist);
446 spin_unlock(&href->lock);
447 return ret;
448inserted:
449 if (ref->action == BTRFS_ADD_DELAYED_REF)
450 list_add_tail(&ref->add_list, &href->ref_add_list);
451 atomic_inc(&root->num_entries);
452 trans->delayed_ref_updates++;
453 spin_unlock(&href->lock);
454 return ret;
455}
456
457/*
458 * helper function to update the accounting in the head ref
459 * existing and update must have the same bytenr
460 */
461static noinline void
462update_existing_head_ref(struct btrfs_delayed_ref_root *delayed_refs,
463 struct btrfs_delayed_ref_head *existing,
464 struct btrfs_delayed_ref_head *update,
465 int *old_ref_mod_ret)
466{
467 int old_ref_mod;
468
469 BUG_ON(existing->is_data != update->is_data);
470
471 spin_lock(&existing->lock);
472 if (update->must_insert_reserved) {
473 /* if the extent was freed and then
474 * reallocated before the delayed ref
475 * entries were processed, we can end up
476 * with an existing head ref without
477 * the must_insert_reserved flag set.
478 * Set it again here
479 */
480 existing->must_insert_reserved = update->must_insert_reserved;
481
482 /*
483 * update the num_bytes so we make sure the accounting
484 * is done correctly
485 */
486 existing->num_bytes = update->num_bytes;
487
488 }
489
490 if (update->extent_op) {
491 if (!existing->extent_op) {
492 existing->extent_op = update->extent_op;
493 } else {
494 if (update->extent_op->update_key) {
495 memcpy(&existing->extent_op->key,
496 &update->extent_op->key,
497 sizeof(update->extent_op->key));
498 existing->extent_op->update_key = true;
499 }
500 if (update->extent_op->update_flags) {
501 existing->extent_op->flags_to_set |=
502 update->extent_op->flags_to_set;
503 existing->extent_op->update_flags = true;
504 }
505 btrfs_free_delayed_extent_op(update->extent_op);
506 }
507 }
508 /*
509 * update the reference mod on the head to reflect this new operation,
510 * only need the lock for this case cause we could be processing it
511 * currently, for refs we just added we know we're a-ok.
512 */
513 old_ref_mod = existing->total_ref_mod;
514 if (old_ref_mod_ret)
515 *old_ref_mod_ret = old_ref_mod;
516 existing->ref_mod += update->ref_mod;
517 existing->total_ref_mod += update->ref_mod;
518
519 /*
520 * If we are going to from a positive ref mod to a negative or vice
521 * versa we need to make sure to adjust pending_csums accordingly.
522 */
523 if (existing->is_data) {
524 if (existing->total_ref_mod >= 0 && old_ref_mod < 0)
525 delayed_refs->pending_csums -= existing->num_bytes;
526 if (existing->total_ref_mod < 0 && old_ref_mod >= 0)
527 delayed_refs->pending_csums += existing->num_bytes;
528 }
529 spin_unlock(&existing->lock);
530}
531
532/*
533 * helper function to actually insert a head node into the rbtree.
534 * this does all the dirty work in terms of maintaining the correct
535 * overall modification count.
536 */
537static noinline struct btrfs_delayed_ref_head *
538add_delayed_ref_head(struct btrfs_fs_info *fs_info,
539 struct btrfs_trans_handle *trans,
540 struct btrfs_delayed_ref_head *head_ref,
541 struct btrfs_qgroup_extent_record *qrecord,
542 u64 bytenr, u64 num_bytes, u64 ref_root, u64 reserved,
543 int action, int is_data, int is_system,
544 int *qrecord_inserted_ret,
545 int *old_ref_mod, int *new_ref_mod)
546
547{
548 struct btrfs_delayed_ref_head *existing;
549 struct btrfs_delayed_ref_root *delayed_refs;
550 int count_mod = 1;
551 int must_insert_reserved = 0;
552 int qrecord_inserted = 0;
553
554 /* If reserved is provided, it must be a data extent. */
555 BUG_ON(!is_data && reserved);
556
557 /*
558 * the head node stores the sum of all the mods, so dropping a ref
559 * should drop the sum in the head node by one.
560 */
561 if (action == BTRFS_UPDATE_DELAYED_HEAD)
562 count_mod = 0;
563 else if (action == BTRFS_DROP_DELAYED_REF)
564 count_mod = -1;
565
566 /*
567 * BTRFS_ADD_DELAYED_EXTENT means that we need to update
568 * the reserved accounting when the extent is finally added, or
569 * if a later modification deletes the delayed ref without ever
570 * inserting the extent into the extent allocation tree.
571 * ref->must_insert_reserved is the flag used to record
572 * that accounting mods are required.
573 *
574 * Once we record must_insert_reserved, switch the action to
575 * BTRFS_ADD_DELAYED_REF because other special casing is not required.
576 */
577 if (action == BTRFS_ADD_DELAYED_EXTENT)
578 must_insert_reserved = 1;
579 else
580 must_insert_reserved = 0;
581
582 delayed_refs = &trans->transaction->delayed_refs;
583
584 refcount_set(&head_ref->refs, 1);
585 head_ref->bytenr = bytenr;
586 head_ref->num_bytes = num_bytes;
587 head_ref->ref_mod = count_mod;
588 head_ref->must_insert_reserved = must_insert_reserved;
589 head_ref->is_data = is_data;
590 head_ref->is_system = is_system;
591 head_ref->ref_tree = RB_ROOT;
592 INIT_LIST_HEAD(&head_ref->ref_add_list);
593 RB_CLEAR_NODE(&head_ref->href_node);
594 head_ref->processing = 0;
595 head_ref->total_ref_mod = count_mod;
596 head_ref->qgroup_reserved = 0;
597 head_ref->qgroup_ref_root = 0;
598 spin_lock_init(&head_ref->lock);
599 mutex_init(&head_ref->mutex);
600
601 /* Record qgroup extent info if provided */
602 if (qrecord) {
603 if (ref_root && reserved) {
604 head_ref->qgroup_ref_root = ref_root;
605 head_ref->qgroup_reserved = reserved;
606 }
607
608 qrecord->bytenr = bytenr;
609 qrecord->num_bytes = num_bytes;
610 qrecord->old_roots = NULL;
611
612 if(btrfs_qgroup_trace_extent_nolock(fs_info,
613 delayed_refs, qrecord))
614 kfree(qrecord);
615 else
616 qrecord_inserted = 1;
617 }
618
619 trace_add_delayed_ref_head(fs_info, head_ref, action);
620
621 existing = htree_insert(&delayed_refs->href_root,
622 &head_ref->href_node);
623 if (existing) {
624 WARN_ON(ref_root && reserved && existing->qgroup_ref_root
625 && existing->qgroup_reserved);
626 update_existing_head_ref(delayed_refs, existing, head_ref,
627 old_ref_mod);
628 /*
629 * we've updated the existing ref, free the newly
630 * allocated ref
631 */
632 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
633 head_ref = existing;
634 } else {
635 if (old_ref_mod)
636 *old_ref_mod = 0;
637 if (is_data && count_mod < 0)
638 delayed_refs->pending_csums += num_bytes;
639 delayed_refs->num_heads++;
640 delayed_refs->num_heads_ready++;
641 atomic_inc(&delayed_refs->num_entries);
642 trans->delayed_ref_updates++;
643 }
644 if (qrecord_inserted_ret)
645 *qrecord_inserted_ret = qrecord_inserted;
646 if (new_ref_mod)
647 *new_ref_mod = head_ref->total_ref_mod;
648 return head_ref;
649}
650
651/*
652 * helper to insert a delayed tree ref into the rbtree.
653 */
654static noinline void
655add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
656 struct btrfs_trans_handle *trans,
657 struct btrfs_delayed_ref_head *head_ref,
658 struct btrfs_delayed_ref_node *ref, u64 bytenr,
659 u64 num_bytes, u64 parent, u64 ref_root, int level,
660 int action)
661{
662 struct btrfs_delayed_tree_ref *full_ref;
663 struct btrfs_delayed_ref_root *delayed_refs;
664 u64 seq = 0;
665 int ret;
666
667 if (action == BTRFS_ADD_DELAYED_EXTENT)
668 action = BTRFS_ADD_DELAYED_REF;
669
670 if (is_fstree(ref_root))
671 seq = atomic64_read(&fs_info->tree_mod_seq);
672 delayed_refs = &trans->transaction->delayed_refs;
673
674 /* first set the basic ref node struct up */
675 refcount_set(&ref->refs, 1);
676 ref->bytenr = bytenr;
677 ref->num_bytes = num_bytes;
678 ref->ref_mod = 1;
679 ref->action = action;
680 ref->is_head = 0;
681 ref->in_tree = 1;
682 ref->seq = seq;
683 RB_CLEAR_NODE(&ref->ref_node);
684 INIT_LIST_HEAD(&ref->add_list);
685
686 full_ref = btrfs_delayed_node_to_tree_ref(ref);
687 full_ref->parent = parent;
688 full_ref->root = ref_root;
689 if (parent)
690 ref->type = BTRFS_SHARED_BLOCK_REF_KEY;
691 else
692 ref->type = BTRFS_TREE_BLOCK_REF_KEY;
693 full_ref->level = level;
694
695 trace_add_delayed_tree_ref(fs_info, ref, full_ref, action);
696
697 ret = insert_delayed_ref(trans, delayed_refs, head_ref, ref);
698
699 /*
700 * XXX: memory should be freed at the same level allocated.
701 * But bad practice is anywhere... Follow it now. Need cleanup.
702 */
703 if (ret > 0)
704 kmem_cache_free(btrfs_delayed_tree_ref_cachep, full_ref);
705}
706
707/*
708 * helper to insert a delayed data ref into the rbtree.
709 */
710static noinline void
711add_delayed_data_ref(struct btrfs_fs_info *fs_info,
712 struct btrfs_trans_handle *trans,
713 struct btrfs_delayed_ref_head *head_ref,
714 struct btrfs_delayed_ref_node *ref, u64 bytenr,
715 u64 num_bytes, u64 parent, u64 ref_root, u64 owner,
716 u64 offset, int action)
717{
718 struct btrfs_delayed_data_ref *full_ref;
719 struct btrfs_delayed_ref_root *delayed_refs;
720 u64 seq = 0;
721 int ret;
722
723 if (action == BTRFS_ADD_DELAYED_EXTENT)
724 action = BTRFS_ADD_DELAYED_REF;
725
726 delayed_refs = &trans->transaction->delayed_refs;
727
728 if (is_fstree(ref_root))
729 seq = atomic64_read(&fs_info->tree_mod_seq);
730
731 /* first set the basic ref node struct up */
732 refcount_set(&ref->refs, 1);
733 ref->bytenr = bytenr;
734 ref->num_bytes = num_bytes;
735 ref->ref_mod = 1;
736 ref->action = action;
737 ref->is_head = 0;
738 ref->in_tree = 1;
739 ref->seq = seq;
740 RB_CLEAR_NODE(&ref->ref_node);
741 INIT_LIST_HEAD(&ref->add_list);
742
743 full_ref = btrfs_delayed_node_to_data_ref(ref);
744 full_ref->parent = parent;
745 full_ref->root = ref_root;
746 if (parent)
747 ref->type = BTRFS_SHARED_DATA_REF_KEY;
748 else
749 ref->type = BTRFS_EXTENT_DATA_REF_KEY;
750
751 full_ref->objectid = owner;
752 full_ref->offset = offset;
753
754 trace_add_delayed_data_ref(fs_info, ref, full_ref, action);
755
756 ret = insert_delayed_ref(trans, delayed_refs, head_ref, ref);
757 if (ret > 0)
758 kmem_cache_free(btrfs_delayed_data_ref_cachep, full_ref);
759}
760
761/*
762 * add a delayed tree ref. This does all of the accounting required
763 * to make sure the delayed ref is eventually processed before this
764 * transaction commits.
765 */
766int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
767 struct btrfs_trans_handle *trans,
768 u64 bytenr, u64 num_bytes, u64 parent,
769 u64 ref_root, int level, int action,
770 struct btrfs_delayed_extent_op *extent_op,
771 int *old_ref_mod, int *new_ref_mod)
772{
773 struct btrfs_delayed_tree_ref *ref;
774 struct btrfs_delayed_ref_head *head_ref;
775 struct btrfs_delayed_ref_root *delayed_refs;
776 struct btrfs_qgroup_extent_record *record = NULL;
777 int qrecord_inserted;
778 int is_system = (ref_root == BTRFS_CHUNK_TREE_OBJECTID);
779
780 BUG_ON(extent_op && extent_op->is_data);
781 ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS);
782 if (!ref)
783 return -ENOMEM;
784
785 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
786 if (!head_ref)
787 goto free_ref;
788
789 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
790 is_fstree(ref_root)) {
791 record = kmalloc(sizeof(*record), GFP_NOFS);
792 if (!record)
793 goto free_head_ref;
794 }
795
796 head_ref->extent_op = extent_op;
797
798 delayed_refs = &trans->transaction->delayed_refs;
799 spin_lock(&delayed_refs->lock);
800
801 /*
802 * insert both the head node and the new ref without dropping
803 * the spin lock
804 */
805 head_ref = add_delayed_ref_head(fs_info, trans, head_ref, record,
806 bytenr, num_bytes, 0, 0, action, 0,
807 is_system, &qrecord_inserted,
808 old_ref_mod, new_ref_mod);
809
810 add_delayed_tree_ref(fs_info, trans, head_ref, &ref->node, bytenr,
811 num_bytes, parent, ref_root, level, action);
812 spin_unlock(&delayed_refs->lock);
813
814 if (qrecord_inserted)
815 btrfs_qgroup_trace_extent_post(fs_info, record);
816
817 return 0;
818
819free_head_ref:
820 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
821free_ref:
822 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
823
824 return -ENOMEM;
825}
826
827/*
828 * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
829 */
830int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
831 struct btrfs_trans_handle *trans,
832 u64 bytenr, u64 num_bytes,
833 u64 parent, u64 ref_root,
834 u64 owner, u64 offset, u64 reserved, int action,
835 int *old_ref_mod, int *new_ref_mod)
836{
837 struct btrfs_delayed_data_ref *ref;
838 struct btrfs_delayed_ref_head *head_ref;
839 struct btrfs_delayed_ref_root *delayed_refs;
840 struct btrfs_qgroup_extent_record *record = NULL;
841 int qrecord_inserted;
842
843 ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS);
844 if (!ref)
845 return -ENOMEM;
846
847 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
848 if (!head_ref) {
849 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
850 return -ENOMEM;
851 }
852
853 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
854 is_fstree(ref_root)) {
855 record = kmalloc(sizeof(*record), GFP_NOFS);
856 if (!record) {
857 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
858 kmem_cache_free(btrfs_delayed_ref_head_cachep,
859 head_ref);
860 return -ENOMEM;
861 }
862 }
863
864 head_ref->extent_op = NULL;
865
866 delayed_refs = &trans->transaction->delayed_refs;
867 spin_lock(&delayed_refs->lock);
868
869 /*
870 * insert both the head node and the new ref without dropping
871 * the spin lock
872 */
873 head_ref = add_delayed_ref_head(fs_info, trans, head_ref, record,
874 bytenr, num_bytes, ref_root, reserved,
875 action, 1, 0, &qrecord_inserted,
876 old_ref_mod, new_ref_mod);
877
878 add_delayed_data_ref(fs_info, trans, head_ref, &ref->node, bytenr,
879 num_bytes, parent, ref_root, owner, offset,
880 action);
881 spin_unlock(&delayed_refs->lock);
882
883 if (qrecord_inserted)
884 return btrfs_qgroup_trace_extent_post(fs_info, record);
885 return 0;
886}
887
888int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
889 struct btrfs_trans_handle *trans,
890 u64 bytenr, u64 num_bytes,
891 struct btrfs_delayed_extent_op *extent_op)
892{
893 struct btrfs_delayed_ref_head *head_ref;
894 struct btrfs_delayed_ref_root *delayed_refs;
895
896 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
897 if (!head_ref)
898 return -ENOMEM;
899
900 head_ref->extent_op = extent_op;
901
902 delayed_refs = &trans->transaction->delayed_refs;
903 spin_lock(&delayed_refs->lock);
904
905 /*
906 * extent_ops just modify the flags of an extent and they don't result
907 * in ref count changes, hence it's safe to pass false/0 for is_system
908 * argument
909 */
910 add_delayed_ref_head(fs_info, trans, head_ref, NULL, bytenr,
911 num_bytes, 0, 0, BTRFS_UPDATE_DELAYED_HEAD,
912 extent_op->is_data, 0, NULL, NULL, NULL);
913
914 spin_unlock(&delayed_refs->lock);
915 return 0;
916}
917
918/*
919 * this does a simple search for the head node for a given extent.
920 * It must be called with the delayed ref spinlock held, and it returns
921 * the head node if any where found, or NULL if not.
922 */
923struct btrfs_delayed_ref_head *
924btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, u64 bytenr)
925{
926 return find_ref_head(&delayed_refs->href_root, bytenr, 0);
927}
928
929void __cold btrfs_delayed_ref_exit(void)
930{
931 kmem_cache_destroy(btrfs_delayed_ref_head_cachep);
932 kmem_cache_destroy(btrfs_delayed_tree_ref_cachep);
933 kmem_cache_destroy(btrfs_delayed_data_ref_cachep);
934 kmem_cache_destroy(btrfs_delayed_extent_op_cachep);
935}
936
937int __init btrfs_delayed_ref_init(void)
938{
939 btrfs_delayed_ref_head_cachep = kmem_cache_create(
940 "btrfs_delayed_ref_head",
941 sizeof(struct btrfs_delayed_ref_head), 0,
942 SLAB_MEM_SPREAD, NULL);
943 if (!btrfs_delayed_ref_head_cachep)
944 goto fail;
945
946 btrfs_delayed_tree_ref_cachep = kmem_cache_create(
947 "btrfs_delayed_tree_ref",
948 sizeof(struct btrfs_delayed_tree_ref), 0,
949 SLAB_MEM_SPREAD, NULL);
950 if (!btrfs_delayed_tree_ref_cachep)
951 goto fail;
952
953 btrfs_delayed_data_ref_cachep = kmem_cache_create(
954 "btrfs_delayed_data_ref",
955 sizeof(struct btrfs_delayed_data_ref), 0,
956 SLAB_MEM_SPREAD, NULL);
957 if (!btrfs_delayed_data_ref_cachep)
958 goto fail;
959
960 btrfs_delayed_extent_op_cachep = kmem_cache_create(
961 "btrfs_delayed_extent_op",
962 sizeof(struct btrfs_delayed_extent_op), 0,
963 SLAB_MEM_SPREAD, NULL);
964 if (!btrfs_delayed_extent_op_cachep)
965 goto fail;
966
967 return 0;
968fail:
969 btrfs_delayed_ref_exit();
970 return -ENOMEM;
971}